If you sell you house in the USA?

Question

and you buy one that costs more then you sold your house for, do you have to pay capital gains?

Answer 1

It has nothing to do with buying another house that costs more - that used to be a rule, but has been gone for many years.

If you owned the house for at least two of the five years immediately prior to the sale, and lived in it as your main home for at least two of those same years, you can exclude up to $250K of gain on the sale, $500K on a joint return, from owing capital gains tax.