I've bought two machines off of PowerMax within the last 5 years. Both PowerMac G3 towers.
Prices are a bit steep, but they supposedly check out these machines first...which wasn't the case with my last PowerMax purchase, which came with a dead PRAM battery and a flaky (to this day) SCSI-based HDD.
In hindsight, spending a couple hundred extra and going for a refurbed Intel Mac Mini or iMac would have been the way to go. You might not need a powerful machine right now, but look into the future, do you feel like buying an old machine every couple of years,or buy one machine near-new that will last longer?
I recommend a refurbished iMac, I did the same for myself and haven't regretted my decision for a minute. Did a quick scan of the refurb page at Apple and this caught my eye (
Refurbished iMac 21.5-inch 3.06GHz Intel Core 2 Duo - Apple Store (U.S.)), pretty good deal.