B&H has the icy dock 4 2.5" drive bays in one 5.25" cage for $43.50 with a $20 MIR, and free shipping. Tax only for NY/NJ folks.
4.5 stars based on 2 reviews.
Newegg has the same one for $.40 more:
Rebate form (good through 1/31)
Rebate can work on a bunch of different models, but this was the one I was looking for. No personal experience with it yet, sorry.