Around £2500 each for a used one. Finding a working one for sale over here is the problem. May as well buy a bust one if you can find one as service kits are available and are very easy to maintain.
You cannot buy a new one unless you buy the complete setup from shooting star in Coney island NJ, Minimum of 4 rifles with compressor and trailer or they will convert your own trailer, Capable of Around 1200 rounds a minute at 100psi or a whopping $20,000 just for 4 rifles . Tried one with a converted bb hopper and what fun it was and you will need an eye watering amount of lead shot for a few minutes of fun.
The 4 i sold have all ended up back in the states as it can be hard to get a single one over there, Prices vary greatly in the states. I sold another yesterday because of this thread so only have one minter left now. Cased and with targets. I owned a 12 gun trailer a number of years back that use to be rented out for galas and fetes.
You can still buy spares and service kits from shooting star.
https://www.shootingwater.com/about.htm
https://forum.vintageairgunsgallery....c-machine-gun/
https://www.youtube.com/watch?v=1OiNQ9wYWoI