2472 is not the actual ID number. If you want to know for sure, ask the guy to get you the stamped ID number on the lower left base and then use the guide below to figure out what it is. A '75-'77 440 carb should be in the 9023-9101 range.
It would have to be pretty spectacular or NOS to get decent money for a mid-'70s unit on a good day but $100 for a dirty, random, unit with no kit? Guy should be paying you to take it off his hands. I have a bunch of them myself just sitting around doing nothing. I've tried selling them, no one wants them.
Thermoquad guide