Because there is difference in the FMV and the purchase price, that amount is treated as a gift. The basis of gift property is the previous owner's basis. It is whatever amount they paid for the house, plus improvements.
If the FMV of the property is equal to or greater than the donor's adjusted basis, your basis is the donor's adjusted basis at the time you received the gift. Pub 551
In addition to this is the money you put into it. You paid $23,678 and $30,035. Add these three amounts together to arrive at your basis.
