The Microfly is a versatile case if you do not mind a couple of modifications. If you are considering the case, buy it for the enclosure and ditch the included power supply.
Only place I know of that has the Ultra Microfly sans PSU is here: Ultra Microfly mATX Case - $55
However it's only $5 less than the Ultra Microfly with 400W PSU over at Tigerdirect. So I recommend going with the Tigerdirect deal instead. Just keep the 400W PSU around as a spare or something. Just don't use it for a gaming PC though. It really isn't that great of a PSU.
i actually have the microfly case i think its is pretty decent i paid about $39.99 dollars, $11.74 shipping plus, 3.62 tax over (total of $55.35) at tigerdirect last December for it. But i got the PSU-less one because i had one.
i dont see it cheaper any were but Tiger.
i put a VIA c7 @1.5GHz a 80GB HD, 512mb RAM, Win xp pro, and an old psu i has lying around. it consumes about 20-30 W during load (prime).
I got mine from jab-tech. It was $70 shipped sans PSU. Not the cheapest but I pay more to buy from sellers I know are not going to give me any issues. I put in an E2160,ECS mobo, and a gig of ram with XP for my step-son a surfing box. The 120mm fan in mine was defective as it was exremely loud but not a big deal to throw a yate in it.