Why not 2660's or 2673's? ... they both have similar (if not better) single-thread performance compared to the models you are looking for and slightly less dua-setup performance. The 2660's you get below 100EUR in EU. The 2673's are the loved ones at the moment and therefore little bit elevated price-wise.
I have an E5-2696v3 QS "QGN7" that I will sell for $777.
This is the functional equivalent to the OEM Production release silicon (same stepping) and is capable of achieving the all-core turbo work-around.
18 cores with an all-core turbo of up to 35x with the right cooling. Top speed (38x) with a 105 BCLK is 3990MHz (effectively 4GHz).