This would be my guess at costs which would make buying a non matching numbers shell a bad investment unless you can do panel and paint yourself.
Engine 6000 (based in my actual costs a few years ago)
Door cards 1000
Dash restore 1200
Rust 10000
Paint 15000 (based on quote)
Wheels 2000
Suspension 1000
Brakes 1000
Seals 1000
Seat trim 1500
diff/gearbox 1500
chrome 3000
carpets, badges, bits and pieces 1000
That said personally I would never pay top dollar for someone else's resto either because there are so many shortcuts that can be taken.