Here's the few lines from my spreadsheet for vendors that offer *any* 6 layer boards in prototyping quantities:
Vendor Layers MinQty 10 in2 20 in2 30 in2 Ln/Sp Min Drill Notes jefy 6+m/s 3 $207 $207 $207 6/6 12 (std) (up to 90in2) myropcb 6+m/s 4 $292 $292 $292 5/5 12 (up to 30in2) PCBexpress 6+m/s 2 $369 $390 $411 7/7 8 doesn't handle silk clears properly. e-teknet 6+m/s 4 $480 $480 $480 7/7 12 note: any size up to 35in2 pcbfabexpress 6+m/s 10 $480 $480 $670 7/7 15
