If you're not in a hurry, I'd keep a watch at Kmart. I got mine there for about $40 - the Graco Cozy Bed, very low to the ground and has side rails that go about half way down. But our Kmart had a good selection. You can keep an eye at kmart online.
My one suggestion if you have a wiggler is to go with plastic instead of wood. I hear my son bonk the side of the bed at night, and I think wood would be awfully painful.
My son just made the transition from our room to his own room and bed this weekend!
For online stores, check these out:
http://shop.store.yahoo.com/dmart/nogtodbedins.html http://www.ababysheaven.com/html/todbeds/8840WW.html
It wouldn't hurt to check out eBay also.