Hello arcos,
I dare say you will struggle to get many people to tell you how much they sell pens for, obviously there is the privacy factor (read secret) but the other thing is some will make pens much quicker than others and will be able to sell them a bit cheaper and still be in profit. There are others who will sell them for what the market will stand(and good luck to them if they can in this day and age). I know a pen maker who sells Sierra pens in a box for £35. I sell the same pens in a box for £42.
Hope this helps
Regards
John BHT