The main pricing decision with cards is not the number. It is what to auction individually and what to bundle.
What to auction one at a time
Anything where condition is debatable, anything with a name attached, anything a buyer would want to see tilted under a light. These are the cards the format exists for.
What to bundle
Commons, duplicates, bulk. Auctioning twenty similar cards one after another drains a room — the attention goes and the prices fall through the set. A lot sells all of them in one go, usually for more in total.
Describe a lot by count and what is guaranteed to be in it.
Starting prices
Low, for the same reason as everywhere: a bidder who has bid once is in. Why.
The exception is a card with a real floor — then set a reserve rather than a high start.
Graded cards price themselves, mostly
A graded card at a given number has a market. Your job is to start below it and let the room arrive.
Raw cards are where the spread is
The same raw card can go for a wide range depending on how well it was shown. This is the direct argument for holding it still, tilting it, and showing the back — a well-shown raw card beats a badly-shown one by more than most sellers expect.
Questions people ask
Should I get cards graded before selling?
For high value, often yes. Weigh the fee and the wait against the spread it removes.
How do I price a lot?
Below the sum of its parts. A lot is convenience, and convenience is the discount.
What if a card does not sell?
Relist with a lower start, or put it in a lot.
More: selling cards, auction or fixed price.