There is a land contract.  Don't know how they arrived at purchase price. The son's purchase price is reasonable based on current property sales in the area. So no, no gift tax return filed.   Land contract only, no mortgage.   They do not share income/expenses.  In fact, son is putting up a poultry barn - father will not be sharing income/expenses.  Father buys/sells cattle - son does not share in the income/expenses.