I understand that that is your preferred interpretation, but I bet that the courts would not agree.   In the US bitcoins are not currency but merchandise; I do not know in Czechia but I bet that the court would take that view.    Courts usually do not count as "loss" a profit that you could have made if you did not give something to the merchant  (in this case, the money that you could have made if you had saved those BTC and sold them today). 

On the other hand you may be able to get damages, if you convince the judge that you lost money because of their fault.   I wonder how you could prove that, though.

But, sincerely, I would not feel sorry for Satoshilabs if they are forced to refund you 3 BTC.  It would teach them not to quote prices in BTC (and, more generally, that business and religion do not mix). 

(Sorry for being cynical.  Maybe I need to take a long break  from this forum.)