Client has installment sale, first buyer left after paying many years on it, but this last year quit paying and did not make any payments.  Client resold in the same year.  She is not related to either of the parties she sold to.  Using form 6252 and I can't see where you can end a previous unfulfilled sale, should I leave them both in the tax return with the original sale as 0 received for last year or take that one out?  She resold the property for a low price due to the previous owner destroying the property.  Client also had to pay the property taxes, where would this cost go?