Everybody going to start using old domains should also know how to get them, I'm going to post soon article about it on seomoz as there are several ways starting from online rankings and lists up to dedicated seo tools that you can run on your computer and get precise and actual data on demand for any domains lists. Anybody intersting in such tools please visit our website: http://en.exdomain.eu/
In theory, you could technically acquire a domain for $10,000 and be able to sell it for $100,000. You could also acquire a domain for $10 and be able to sell it for $100,000, $10,000… or $100, you get the picture. Because of this, it’s hard to recommend a perfect starting budget because your strategy, experience, and the pace at which you learn will hugely affect your buying and selling decisions.