The number people quote when they ask how much it costs to get cards graded is the per-card fee on a service level, and that is the smallest part of the answer on a small submission. What you actually pay is the fee times the number of cards, plus the extras you ticked, plus insured postage in both directions, and the figure that decides anything is the total divided by the cards.
What you are actually paying for
A grading submission buys four things: the examination, the holder the card is sealed into, the certification number that lets anyone verify it later, and the return journey. The fee published against a service level covers the first three. The fourth is charged separately by almost every grader, usually as an insured return shipment priced against the declared value of everything in the box, and it is the line people forget.
The fee is set by declared value, not by the card
Service levels are tiered by the value you declare for each card, and the tier you must use rises as the declared value rises. That is why there is no single answer to what grading costs: a common card and a card worth thousands go through the same building and are charged differently, because the grader is carrying the insurance risk in between. Read the tier table on your grader's own page before you cost anything.
Postage is per submission, so it is per card only in arithmetic
Sending ten cards and sending two costs roughly the same in postage, which means the postage share of each card's cost is five times higher on the small submission. This is the single biggest reason people are surprised by the bill. If you are weighing whether to send two cards, cost them honestly with the postage in, and then consider whether waiting until you have a fuller box is the better move.
Then read the break-even
The grading cost calculator on this site prints the cost per card and calls it what it is: the amount each card has to be worth more graded than raw before the submission has paid for itself. That number, not the fee, is what you carry into the decision about whether any given card is worth sending at all.
Questions people ask about how much does it cost to get cards graded
Why does this site not publish the graders' prices?
Because the fee tables change and they are the graders' own to publish. We also could not read one of them: a major grader's service page refuses our reader outright, and we record that rather than guessing around it. The calculator takes the fee as an input and names the page you read it from.
Is a faster turnaround worth paying for?
Only if you have a reason to have the cards back by a date. The grade does not change with the service level, so the premium buys time rather than outcome, and on a card you are keeping the time is worth nothing.
Should I insure the return shipment?
You generally have no choice, and you would want to anyway. The return leg carries every card in the submission at once, so the insured value is the whole box rather than one card, and that is reflected in what the grader charges.
Does the cost change if the cards come back badly graded?
No. The fee is paid for the examination, whatever it concludes, which is why the honest way to cost a submission is against the grade you will probably get rather than the one you are hoping for.