How much to pay for this domain name..?

I'm building a biz/website and one of the websites I reference for time to time(mostly for design purposes) is no longer there. While this may not bode well for my biz I'm not too worried... without going in to detail you could tell they didn't know what they were doing.

I think I can pick up the domain at auction for under $30. The users of this website/biz would likely be interested in what I have to offer but I have some concerns:

1. Not sure how old the site is but the domain has been registered by one person/company for over 10 years.

2. I can't find anything regarding the demographics on the visitors to the site. Alexa and Quantcast have no information.

3. I found a Facebook page for the site with over 30k users but I can't find anything about the demographics... I could have sworn FB would give you that information before. The FB page did have some activity about a year ago with some likes and they look legit but being that the page has been vacant for over a year would you make an offer on it?

4. If I do pull the trigger and get the domain is my best bet just to redirect the domain name to my website?

Thanks, Adrian