Ok I've been perfecting the PCB and double checking prices.
It looks like I can easily make them for $10 each.I'll plan how I'm going to organize distributing them and then I will start making.
Sounds good 
Let us know when they are ready. I think I'll order some 
(and hopefully the shipment costs aren't that much...)
And thanks for the answer kuk!
Regards,
Atmoz