I ordered the frame kit from Fyne, something that shortened my building time but increased the cost. Another thing that drastically could have saved me some money was the Epoxy. I started out buying West Epoxy which is hard to find and very expensive in Poland, eventually I found a local manufacturer LaminoPol which had a very nice product at a third of the West price..... So had I gone local from the start I would have saved almost 300Euro!!!
So these where the main parts of the material cost:
Plywood: 300Euro (I bought too much as I did not need ply for the frames)
Frame kit: 710Euro
Solid wood: 660Euro (ready cut and planed to the right dimensions)
Epoxy: 680Euro (still have around 4 liters left which will be plenty for he remaining jobs)
So a grand total of: 2500Euro or about 3200USD
I am happy this was spread out over almost a whole year!