Here's a test I have in process. I bought an old $5 closeout domain from Godaddy TDname expired auction. I put a quick minisite up and linked to it with a crazy anchor text phrase. The domain is ranking for that crazy term now. It's gone through one pagerank update and I'm waiting for a second to come. Then I'll redirect the domain to another minisite. I suspect the second site won't rank for the anhor text, but we'll see.
It's ranking high today! What could be the problem? NO. JUST STOP. Unless you know the entire history of a domain, you may be setting yourself up for failure before you begin. SEOs (and business owners) use a variety of tactics to get a site ranking high in search results. For some of these methods, we'll just call them "questionable". These methods could include everything from buying links, overuse of directory submissions (non-industry related), duplicate listings, poor quality backlinks, and guest blog comments.
Yes! Selling domain is an emerging trade and no wonder if it can develop into an exchange. www.DomainX.org has been initiated with this view. There are some good ideas in the comments regarding which names to buy and how to grow their value. However one must not forget that it also involves a recurring cost (annual renewal) and keeping many of them might become difficult if you are not really selling at least a few to cover it. Enjoy free listing at DomainX.org.
I have an interesting twist on how I have done it in the past. I will buy a domain and use it as a development domain for blog posts and things of that nature. Then over time it will gain DA and PR. Then I will sell it off and buy another development domain and start the process over. Not quite the process you mentioned, but it works. People will link to the development site to show things off as well sometimes, so that helps.
There’s an important distinction to make here between domain flipping and website flipping. The latter mainly refers to buying and selling full websites. By full websites, I mean websites that actually have content and more often than not have traffic and revenue. When buying and selling websites, the domain name matters less as the main value there is the content, traffic, revenue, history/reputation, sustainability and growth opportunities. The same can’t be said for domain names where you’re just selling “the name” and hence it’s all that really matters.