I went way beyond my initial budget. But it didn't really bother me as I was having a lot of fun buying things here and there because I decided to go carb instead of FI but that's a whole different can of worms.
To your point though, with a pallet donor parts and basic kit (assuming no back ordered parts to slow you down), the things you'll still need to obtain by purchase or borrowing, tends to be tools; not a whole lot - in my case I did get both a manual and a pneumatic riveter. I also bought about 6 drill bits (3/16" and 1/8"). Also some metal shears - the alum. panels aren't always 100% perfect when interfacing with the body.
Stuff you'll need "New", unless the donor wheels and tires are in very good shape:
* tires
* Grease
*
Oil
* Coolant
* transmission fluid
* rear-end gear lube
* brake fluid
Depending upon how the condition of the engine and all related wires, hoses, filters, etc, as well as possibly keeping certain power units attached to the motor, you may still need:
* various engine belts
* various hoses
* plug wires
* sensor harnesses
* air filter
*
oil filter
* spark plugs
* power steering fluid (if keeping.)
* AC Refrigerant (if keeping)
* distributor cap, rotor
* rattle can Paint (if you decide to at least freshen the engine's looks)
* gaskets
This could obviously get longer depending upon what you find when you tear down the engine. If it's a high mileage motor, consider a hone and ring job at the bare minimum but if you're going that far, may as well replace main bearings and inspect cam, lifters, etc....
Just my wooden nickel.