Start Here: Everything You Need to Know About Grading For Profit
Explaining everything from buying profitable cards, grading PSA 10s, and keeping good data.
This is going to serve as both an introduction to this newsletter, and a complete guide on how to grade for profit.
This post will go through some of the foundational parts of our business that helped us earn over 24% net profit margins in 2025. I will also provide links to resources I’ve created that explain concepts in more detail.
Business Overview
Our business is based on buying cards on eBay, grading them with PSA, and selling them. We take a probabilistic approach. We look for cards that have a chance or a probability at grading as a PSA 10, and we use Expected Value to see what price we can pay for these cards to make a profit. We primarily buy on eBay, and we primarily sell on eBay (but with PSA Vault as our consigner).
Expected Value & Expected Profitability
We use an Expected Value model to determine whether or not a card is profitable to buy. I’ll give a very simple example of Expected Value for those of you who aren’t familiar.
Expected Value is a probability based measurement of the value of something. Let’s say you have a lottery where you have:
A 50% chance of winning $5
A 50% chance of winning $0
The Expected Value is equal to:
$5 x 50% + $0 x 50% = $2.50
The $2.50 is equivalent to the long-run average winnings from this lottery. Note that in the analogy above, grading a card as a PSA 10 represents “winning the lottery.” This is where the profit is generated.
You can read our Complete Guide on Expected Value here.
Looking for PSA 10 Candidates
Our goal is to only buy cards that have a chance to grade as a PSA 10. That chance could be 10%, 50%, or 90%, depending mainly on what percentage will give the card a positive Expected Profit.
When buying on eBay, it’s hard to see the surface of a card well. We make our buying decisions primarily based on cards that have good centering and sharp corners, although we do our best to evaluate surface and edges as well.
You can find a complete guide to finding PSA 10 candidates on eBay here.
And you can find our guide to creating optimal search filters on eBay here.
Pre-Grading
We reevaluate all cards once they are delivered from eBay. We generally at least find minor issues that weren’t seen in the listing, but in most cases, they are still PSA 10 candidates.
We inspect the same things that PSA inspects: centers, corners, edges, and surface. Again, we only submit cards that we feel have a chance at grading as a PSA 10. Remember, it is very important to take a probability based approach because there will always be subjectivity in grading. You will never know for sure whether a grader will give a card a PSA 10, PSA 9 or even a PSA 5.
Note that the cards that we don’t submit end up being sold ungraded, usually for a small loss. This is because we usually sell the card for a price similar to what we paid, and the loss will consist of fees and shipping costs.
Selling raw cards leads to losses, but selling PSA 9s generally leads to larger losses due to the cost of grading. As a result, it is important to be smart about what you submit. There is a fine line between submitting cards that are imperfect but still PSA 10 candidates, and just submitting bad cards. The only way to find this line is experience, and we still make mistakes from time to time. Practice makes perfect.
You can find a complete guide to PSA Grading here.
Why We Lose Money On 50% of Cards
Because of the nature of expected value, we are fine with losing money on cards that we sell without grading, or that grade as PSA 9s. Believe it or not, this is actually a strategy that leads to consistent monthly profitability.
This works mathematically because the Expected Profit of a card will only be positive if the gains are significantly larger than the losses. In spite of losing money on 50% of the cards we buy, we made a 24% net profit margin in 2025.
Sourcing PSA 10 Candidates on eBay
We buy all of our cards on eBay. We primarily buy sports cards and Pokémon cards around the $100 to $1,000 range, although we occasionally go above or below these thresholds. Unlike most resellers, we generally buy cards while they are hot, or while the value is at its peak. The key thing to remember here is that just because a card has reached a new high, doesn’t mean it can’t keep going up. Cards of players coming off of big games or big seasons are very appealing to us, as these tend to be the most profitable cards to grade. We also like buying cards from new product lines, but with adjustments since these cards are likely to fall in value in the short run.
You can read more about what kinds of cards we buy and why here.
And you can look at specific case studies of cards we bought here and here.
Selling through Consignment
We sell cards on eBay, but we use PSA Vault as the consigner. Their fees are slightly lower than selling directly on eBay, but you can find consigners elsewhere with lower fees.
We mainly use PSA Vault for the convenience. Once we ship the card to PSA for grading, we don’t have to worry about it again. As a result, we don’t need to worry about listing cards for sale, shipping cards, or interacting with the end customers. This gives us more time for other things in the business (and for writing this newsletter).
You can find an example of the risks that can come with using a consigner here.
EV Spreadsheet
We have a spreadsheet that allows us to quickly calculate the expected value of all cards. We input the gem rate, the PSA 10 value, and the PSA 9 value, and the spreadsheet determines the Expected Value and the maximum price we can pay for a card.
I used conditional formulas in Excel for this, which limits the amount of work we have to do by hand each time we evaluate a card.
We save all data for cards we evaluate. This means if we see a Drake Maye Prizm Silver card today, we will have the data readily available if we see another one next week.
Accounting Overview
The inventory management is a bit tricky for this business. To address this, our inventory management spreadsheet has a few different important features.
All inventory is given an Inventory ID Number to help us track it. This is especially helpful when we have duplicates of the same card.
The spreadsheet has a “Status” section, that helps us keep track of cards. For example, it tracks whether a card is being shipped to us from eBay, is being graded with PSA, or is available for sale.
The spreadsheet tracks the full inventory value of all cards we own. In other words, we keep track of initial cost less refunds plus grading costs for each individual card.
We use our spreadsheet to input data into our Wave accounting application monthly to create our financial statements.
I’ll break down some of these features in more depth in future posts, but for now, just know that it takes fairly meticulous record keeping to run a grading business with moderate scale.
Data Keeping
We keep a ton of data that helps us improve our decision making (although I would like to keep more). There is a tradeoff between keeping data and saving time. The more data you keep, the more time you have to spend inputting that data into a spreadsheet. So we try to keep things that are relevant to our business and our decision making, without creating too much extra work.
For example, we keep track of our grading results, our grading notes, and our expected Gem Probability for every card we submit. This helps us refine our grading process and grading knowledge.
There’s a lot more I could write here, but for now, I’ll point you to an example of how we used this data to decide to be more aggressive when buying inventory. You can find that here.
Also note that Excel skills help a lot for all of this. I highly recommend anyone taking card reselling seriously to spend some time learning pivot tables, VLOOKUPs, and other intermediate level Excel skills.
Conclusion
That’s all for now. I highly recommend you bookmark this post and use it as a guide when reading any of our articles. Thanks for reading!