"payoff" or a number in the sales contract?

Foreclosures, Short Sales, Tax Foreclosures
1

Which practice works better with the mortgage companies?

  1. having the owner sign 3 blank contracts and filling the number in later to negotiate

or

  1. having the owner sign 1 contract with “payoff” in the price field
2

no one should ever be asked, nor sign a “blank” contract…