i frequent craigslist and often see entire setups for sale dirt cheap. I'd just mind what the system is. I wanted a pre-drilled tank with factory overflows and a lot of people set up fresh or saltwater aquariums without them. Electric stuff like pumps, heaters, and lights, you just take your chances when buying used. I didn't place a lot of value on a system where the price was weighted by fish because I wanted to have established water chemistry before adding fish and a move from seller's house to mine might mean an entire cycle again. I suppose there are alternatives, like LFS
babysitting for a few weeks. Sounds like you're doing what I'm doing now. It's been a lot of fun so far and this website is incredibly helpful. I just added my first fish a few days ago after about 5 weeks of break-in. I'm probably still to early with it, but the clowns and tangs seem really happy so far.