This is the first I've seen any quantity of CX3 Pro dual 10Gb boards under $100. I'm a little iffy on this one because they're shipping from China but we haven't seen any counterfeit Mellanox cards yet so I'm going to hold on to the hope that these are DC pulls.
Mellanox ConnectX-3 EN CX312B 2-Port 10GB MCX312B-XCCT Adapter 8011467808582 | eBay
Here's a bonus: CX3 non pro, $50/ea shipped -- I'd reach out to the seller on this one, you may be able to get these closer to $40-45 with combined shipping.
Mellanox ConnectX-3 MCX312A Dual Port 10 Gigabit Ethernet RMDA/RoCE | eBay
Mellanox ConnectX-3 EN CX312B 2-Port 10GB MCX312B-XCCT Adapter 8011467808582 | eBay
Here's a bonus: CX3 non pro, $50/ea shipped -- I'd reach out to the seller on this one, you may be able to get these closer to $40-45 with combined shipping.
Mellanox ConnectX-3 MCX312A Dual Port 10 Gigabit Ethernet RMDA/RoCE | eBay