Dang, I must be the odd man out, but whenever I need soemthing like a new grip, magazine, spring or spring kit, holster, sights, etc.etc. I always check e-bay right along with Midway and Brownells. Ebay seems to often have the very best price, and often with free shipping (which is especially nice when ordering some piddly $2 spring or screw, that some of the big boys will want friggin' $9 to ship).
Sure, you gotta be wary of who you're buying from, but I've had very positive results with them. Plus, they're all so desperately worried about their feedback rating, they usually have me a tracking number within the hour, even when I order at 11:00 at night LOL!!