@ggliverette if the sale was within a short time after the demise of the decedent, then people often take the easy route and use the sales price as the FMV. If there was a time gap and also because the title was changed , it complicates things a bit . You can always use the tax assessors' figures which tend to be a bit on the lower side ( thus creating taxable profit for the inheritors ) or get a realtor familiar with the neighborhood to give you an estimate.
Even if the title was not changed, you would still get a 1099-S, it is only that the 1099-S would have been issued to the Estate/ Trust and thus easier to handle and the basis is only based on one date ( or an alternate date within six months ) -- now you have to dates -- FMV at death , transfer date and finally the sales date . I may be just complicating a simple case . I would suggest using the FMV at death the same as the final sales price , if this all took place within a reasonable time ( such as one year from the date of death ) and if your local real-estate market is generally slow moving.
Good Luck