66 Dart sold

Got a good cash offer on the 66 today, 4 large more then i have in it! I told the guy i would have to think about it, He want's a answer tomorrow and has cash in hand!Am i nuts for thinking about it?? Clean cars are hard to find up here but i have an eye on a 66 Charger it's as clean as my dart with no engine or trans, it's biggest down fall is it's red on red which i absolutely hate.