Be VERY careful with your business model. They have great one-word domains, you can only buy: lousykeyword1keyword2.com domain. That is a huge difference. Remember the number of businesses is not limitless; those who are serious will buy one-worder (keyword or brandable) or a GREAT two-word domain rather than lousykeyword1keyword2.com domain.
If you are new to the online world, buy a good domain and start working on your website NOW rather than live in the hopes someone, in a few years, maybe, will pay you a few hundred bucks for your domain. Do not waste your time for making up new keyword combinations or reading news to possibly get a new "POTENTIALLY" hot keyword in several years. You will be better off writing two good articles a day and adding new content to your website.