I had a qoute from pcbcart for a 4 layer board of our size with gold finish and 240 connection pinns for the DIMM ind 1.2 mm thikness resulting in 18 euro per board  for a quatity of 10 boards.

I would like to avoid manufayturing the boards in germany. The liddle to no increase in quality often doesn't justify the price over the asian manufacturers in my experience.

@Olaf.Mandel:

Wich size of the board did you set for your design and your quote ?

I tought of increasing the heith  of the daughterboard above standart DIMM size to 50 maybe 60mm to get more space.

I also think we will have to populate the backside with capacitors anyway.The Xilinx docu tells to put the smallest capacitors right behind the Vint and Vcc vias.
So having to additional layers for ground and signal would be a  plus.

Edit: just to have a frame of capabilitys we are talking about here. The restictions published by pcbcart:

Layers                         1-10 layers
Material                         FR4
Copper Thickness         1/2 to 2oz  (18um-70um)
Board Thickness         .016-.126"  (0.4mm-3.2mm)
Surface finish                 HASL,Ni/Au,OSP
Soldermask                 LPI, different colors
Board Dimension         600x700mm
Min Hole Diameter         8mil (0.2mm)
Min line width                 8mil (0.2mm)
Min line spacing          8mil (0.2mm)
Min SMT pitch             16mil (0.4mm)
Min. Annular Ring         .008" (0.2mm)
Aspect Ratio                 5:1
Surface/hole plating         ave. 25um min. 20um
Tolerance:    
Hole Tolerance (PTH)      .002" (0.05mm)
Hole Tolerance (NPTH)    .003" (0.075mm)
SM Tolerance (LPI)        .003" (0.075mm)
Dimension                .004" (0.1mm)
Electrically test                10V-250V, flying probe or testing fixture