To look up baseball card value you need two things right: the query and the filter. The query has to describe the exact card rather than the player, and the filter has to be on completed sales rather than on what people are asking. Get both right and the rest is a minute of arithmetic.
Describe the card, not the career
Search the year, the set, the card number and the player together. A search on the player's name alone returns every card that player ever appeared on, across decades and dozens of sets, and averaging those is meaningless. The information you need is on the back of the card.
Use the sold filter before you read anything
Every marketplace shows active listings first. Switching to completed sales changes the numbers, often substantially, and it is the only view that reflects what buyers have actually paid. Do the switch before you look at prices so that no asking price anchors your expectation.
Keep raw and graded apart
A graded card sells into a different market than the same card raw, and at a different price. If your card is raw, read raw sales; if it is graded, read sales at your grade. Mixing them is the usual cause of a spread that seems to make no sense.
Five results, two thrown away
Take the first five matching recent sales, drop the highest and the lowest, and average the middle three. The card value checker does this and shows you the straight mean beside it, so the effect of any outlier is visible rather than hidden inside the answer.
Questions people ask about look up baseball card value
Can I search by image?
Image search can sometimes identify a set and it does not reliably distinguish parallels, which is exactly what decides the price. Read the card's own text.
What if there are hundreds of results?
The query is too loose. Add the card number and the set, and the result list should collapse to the card you are holding.
How far back should I look?
A few months for a card that trades often, longer for one that does not. Consistency of the card matters more than recency of the sale when comparables are scarce.
Do sold prices include postage?
Sometimes bundled and sometimes separate. Read them the same way across all five, or you introduce a difference that is not about the card.