PM me with the prices that you find on Accuride slides. I'm a custom cabinetmaker, and our shop uses these glides. I'm almost positive I can get you a pretty good deal on whatever you find.
Keep in mind that there are different types of slides which have different weight ratings. For example, the 7434's are for standard drawers that you would use for silverware or lighter objects. 4034's are for file drawers or pull outs (recycle, garbage, full-sink, etc.). We've used some slides that were around $500 a pair. They were rated at 300 lbs and the ball bearings were about a 1/2" in diameter. If you plan on using it for tools, automotive supplies, etc., you're going to need higher rated slides. If you plan on using it for topo maps, you'll be fine with the lighter rated ones.
Eric