Can't imagine these get any cheaper. I'm not ready for them yet but they showed up on my watch list
Lot of 3 Mellanox ConnectX-2 Single-Port SFP+ 10GBE Network Card MNPA19-XTR
Lot of 3 Mellanox ConnectX-2 Single-Port SFP+ 10GBE Network Card MNPA19-XTR