For my first conversion, I'm switching a '77 Schwinn Super Le Tour 12.2 to a single/fixie. Its got a pair of the original Araya 27" wheels on it right now, but I have new Tektro brakes with about 1/2" to drop on the caliper, so I've decided to buy a pair of 700Cs.

I've been reading up here in the the forums and spending a lot of time over at Sheldon Brown's site and have decided to go with the Mavic CXP-22s with the Formula flip/flop hubs.

None of my LBSs have them available, so I need to get them online. Harris Cyclery has them for $200 (the black ones) as does WheelandSproket.com . Bicyclewheels.com has the same black ones for $150... what gives?
The shipping on all three is about $20-$25... and I've read the specs and am pretty convinced that the rims, spokes, and hubs are all identical. So, why the price difference?

Anybody have any thoughts? Is it safe to go with the cheaper bicyclewheels.com option or should I shell out the extra $50 for the ones at Harris?