Well they need to say that on their website and they don't so I expect 3 BTC which is what I paid. Do you have a law degree?
I don't have a law degree, but I was recently reimbursed by my Swiss employer for my expenses abroad. They paid me Swiss Francs with the rate on the day of the expense. I'm pretty sure it is legal and I'm also pretty sure you are getting Czech Crowns if you ever get a refund. Does your lawyer has a Czech law degree?
That said, I'm still willing to pay you 330USD for the device.
My lawyer has an International Business & Economic Law degree, so I think he knows a little more than you.
$330 is insulting for my device, not only is the device rare as well as it is limited, and first edition. The device is probably worth more than 3 bitcoins and for sure in a couple of years I could probably get a good price for it.