does it not have a configuration, might be able to manually set it to a different mhz
I do not know how to change the freq, if it is possible at all. You can check out the app for it......DataDash is the app that you monitor it.
I think that you can change it only in the LPWAN Dev Kit and not in the M2 Pro miner.
As I check from their official store, the price for a brand new in the EU is €2100. Perhaps you should reconsider the price that you are selling it?