1966 mustang is it worth it?

I'm 18 and want to restore or finish a 1966 ford Mustang with my dad. This 1966 mustang runs good is automatic no rust has a rattle can paint job which I would change and the person only wants $5000 which I want to lower to $4000, it is in good shape on the inside he just put new upper/lower A-arms. New tie rod ends. New brakes & shocks. New gas tank & aluminum radiator. New driveshaft. Zero rust. 200ci/auto. Is it a good deal? I don't want to put like $20000 in to it.

No 66 is one of the worst years of mustang that's a girls car the 200 iv is extremely slow espicaly with the automatic transmission of pass without a second thought find somthing cool to fix up like a old chevelle or even just a 68 mustang. But defintly not a auto 66 with the 200

" I don't want to put like $20000 in to it." Then walk away now. The 200 I6/auto combo is the most undesirable combo possible for 1966. You can of course put a larger engine, different transmission, etc. In it, but you'll have to upgrade some of the components as well. You'll have to change out the motor mounts, upgrade the front suspension, get better brakes, new radiator, new exhaust, reinforce the chassis, etc. It's going to get expensive pretty quickly. Plus I'm sure you're going to want new paint job, and probably restore the interior. So right off the bat even if you don't do any major mechanical upgrades. The car is $5000 and a decent new paint job will be around $3500, I'm assuming the interior is going need some work, so plan on another $2000 for that. So you're already a bit over $10k. For a Mustang that's never going to be as desirable as the V8 or fasback models.

If you're going to spend that kind of money, you should get something that you really want or something that other people will be knocking down your door to get should you want or need to sell it.

Any 1966 Mustang is a classic and they bring way more than they are actually worth. It will be worth more as the years go by.