Should I buy it? 1963 Chrysler Imperial

It's as big as a pickup truck and at least as heavy as a pickup truck. Fuel mileage will be similar to a pickup truck. 9 MPG/city 11 MPG/hwy or so. If you'd DD a pickup, why not.

Unless it's in showroom condition it'll probably never be worth a lot, the market is small. Mechanical parts are standard early 60's Mopar stuff and available, body and trim stuff will be impossible so look for a complete car with everything working.