Well, it looks like a diamond in the rough for sure! Even if the guy gave you the car for free its going to test your resolve and determination to finish it. This post has got me to thinking about how far one goes to "restore" a project car...for me, that means bare shell, sandblast it, cut out all the rust, all new or rebuilt everything, but that is not what every other person may want to do, soooo, you and your dad know what it takes and what level of ocd issues you have that will guide YOUR restoration project....and not every one wants to convert it to a V8 canyon carver type rig. I think you have expressed yourself well enough to know that you and dad would be able to tackle this project and have some fun while doing it, with out breaking the bank, even if you loose some money on what you spend vs what it would sell for. I would have a serious conversation with the owner about the condition and cost to get the car looking and working the way you want ...offer him 250, explaining you have had a chance to look into parts and labor, he will say no, then walk away and give him a few days to think it over, recontact him and see if hes willing to accept it, he may counter at 500 or more but I would not go over 500 though,as pointed out previously, the initial purchase price is not the main consideration, its understanding what amount of money and time is going to be needed in getting it to the level you want it to be. Best of luck!