Do you trust PSU included w/ case?

I'm planning on building a new PC, and I've noticed that a lot of the cheaper cases come with included power supplies. Are these decent power supplies, or am I better off spending an extra $50 and buying a better case and adding a brand-name PSU?

Some of them are quite good. The Chieftec and Antec cases with PSU's are OK.

if the case is under 40-50 bux ur taking a chance

I use cheap case w/ cheap 400 watt power supplies all the time (on cheap low end PC's of course). Dont have much trouble, here and there a PS blows or fires a Motheboard but hey, part of business

if ur buying a bad ass PC, dont go for CHEAP

Second question:

I'm thinking of buying a Cooler Master case that comes with a 350w PSU. I know Cooler Master is a reputable name, and the case is about $100. Will 350 be enough power to run an Athlon 64, 1 GB RAM and X800 system? How can I figure out how much power I'll need?

I only use Antec power supplies. I've yet to see one fail.