It is best to list the cost basis as accurately as you can. If you don't have records from earlier than 2003 (which is a significant amount of time past 1982) you may want to enlist some assistance from a professional to determine the approximate value of the land at the time of the inheritance.
Keep in mind that the cost basis of an inherited asset is the value of the asset on the date of death of the person from whom you inherited (unless the estate elected an alternate valuation date, which is not common.)
In TurboTax, only report your 25% share of both the basis and the sale to calculate your individual gain.
It is best to list the cost basis as accurately as you can. If you don't have records from earlier than 2003 (which is a significant amount of time past 1982) you may want to enlist some assistance from a professional to determine the approximate value of the land at the time of the inheritance.
Keep in mind that the cost basis of an inherited asset is the value of the asset on the date of death of the person from whom you inherited (unless the estate elected an alternate valuation date, which is not common.)
In TurboTax, only report your 25% share of both the basis and the sale to calculate your individual gain.