the BRNO 601 is a short action Mauser and will not fit much longer cartridges than the 223.
I have one that i rechambered to 22-250.
Essentially i guess you will pay what you think you should if you want it enough.
I like mine, but I was having feed issues and scope alignment has been a challenge.
The rechamber seemed logical at the time and i dont regret it, but it has created more problems than it solved.
These things could be specific to my rifle and i dont want to say that all 601's are like mine.
It is an excellent short action Mauser with a set trigger that sold cheaper than most due to USA import bans on communist firearms thus limiting the market to Canada and Mexico in north america.
If it comes with glass, i dont think 600.00 would be unfair, 500.00 without.