What are you basing that on?Sam I appreciate your input. The car has been rebuilt. It doesn't need 20k invested, the only thing potentially wrong it the window regulator / motor is going out.
Have you inspected the car personally? Have you sent the car for a reliable and independent PPI? Are you taking the word of the seller (because seller don't lie, right)?!
Again, do the legwork first. THEN ask for advice. For starters, negotiate with the seller first and see where you stand. Then contact your bank and see if you can get financed. Then contact your insurance company to see if you can get insured. Then find a place where you can get the car inspected (PPI). Get the PPI and see the REAL condition of the car and how much it might cost to fix it to near mint condition (a PPI at a Lamborghini dealership would be best for this). To sum it up: find out if you can afford it, can insure it, can fix it. AFTER all this, you will know what it will cost and you will be in a better position to know whether or not you can recoup this on a sale. If you are still unsure or want confirmation, then you can ask here. There are many knowledgeable people who can assist you then but right now it is just meaningless speculation.