I run a 25a Radio Shack PS and power a pr of 0610iNet Hyperion chargers and have not had any probs chanring pairs of 3S 5000 lipos. I use it to run a single 0610i charger to charge a123 5S1P pacs at 10amps.

I have a ProPeak 20a PS which has also proven to be reliable. The Pyramid supplies have a good rep as well. These are all in the price range you're looking at. If you need more amps, Pyramid makes a 30a and PowerForce has a 40a supply.