to buy or not to buy

[240_de_Ville]

i wanted to make this a poll but i have no idea how. ok i have an 89 240. i believe it is the se model..its got power windows,mirrors, and did have cruise(stopped workin one day) and a rear windshield wiper. a buddy of mine has the same car but none of the options listed above. he told me he would sell it to me for 500 bucks..the kisker is the compression is 90,60,60,60..and it wont start. i tried to start it today and it really wanted to but just couldnt. i know there is a problem with the radiator (it leaks) would that be the reason it has low compression and wont start? i could prob use some of the parts from it to make one complete decent car. so i guess here are my different options...

1) buy the car and use what i can and sell as is

2) buy the car and use what i can, try to rebuild that engine and then sell the car

3) buy the car use what i can and part it out

4) pass it up completely

i mean its 500 bucks...and the wifey even agreed that it really wouldnt set us back financially. i'm not good with money so i want to make a good financial decision with this....sorry bout the long post just wanted to cover all the bases and i want to know what you would do if you were in my decision. thanks for the input.