Perpetual money pit?

Hello Folks,

I know very little about car repair. However, I have this weird thing for old small convertibles (Midgets, Sprites, Spiders, etc.). Unfortunately, my understanding is that these two points are in direct contradiction. If I were to buy one of these little guys on the cheap, it is my uninformed belief that the car will be non-running more often than not. So, I have some questions for you "experts":

1.) How much should I be willing to pay to get an old, running one of these guys? I see prices anywhere from $3000 to $17000, but doubt paying 6 times as much will provide 6 times the reliability.

2.) How much should I expect to spend on keeping the thing running for non-daily driving responsibilities?

3.) Is there any way to make this work so that I don't lose a small fortune over time (assuming I sell it some day, really I guess this is just a repeat of question 2)?

4.) I know this is short on details, but is there any way this is worth it: