i bought 8gigs @ 349.95 (4x2g moduals for my mac pro 8-core early 2008 model)
and 4gig (for my mbpro early 2008 trackpad model) @ 89.95

from OWC (www.macsales.com)

they shipped fast, was packaged well, and came with very good directions as to why the mac pro memory riser boards had to be filled in a specific order for maximum speed.