66 Cuda question

The main reason I ask is the radiator shop that builds the bus radiators where I work I asked him how much to rebuild mine and he says because of the round tanks he has to build my core using my radiator. No problem was my answer how much his answer was I cant give a price until I build it. Ok around what price so i am prepared he says not sure. So I dont want to have to pay him more than new if he wont shoot a round number within 100 dollars.