Supermicro AOC-STGF-I2S PCIe Intel X710 Dual Port 10gb SFP+ Network Card | eBay
<p>Tested on an open test bench.</p>
www.ebay.com
This came up in the saved search I created several months ago. It may not be a great deal, but it's probably an OK deal. Please do your own research.
I ended up purchasing 2x Lenovo 00JY823 (Emulex OCE14102) for $10/each and Mellanox CX312C for $20.