Lots of worthy advice for you to mull over there. I suppose the bottom line is that one has to really want to do such a project. There is so much more to consider than the initial acquisition costs. But I doubt there are many on this newsgroup who regret embarking on their projects.
I liken it to the art of collecting, anyone who collects for money is doing it wrong and missing the point. The main reason should be fun and enjoyment.