Thank you for your reply.
Sorry, I do not know good English.
Yet you write some questions later.
You have to understand that I want to pay a lot of money and I care.
I think 10 Units (what u call "alot of money") seem to be a normal order.
Maybe check the childboards for your language to get more informations about mining, because your english seem to be not realy good (no criticism).
Regards