I paid £300 for a reasonable .22 model two years ago.
I saw a .25 at Bisley a few more years ago for £525 but not with your short barrel.
They are PCP and came with a pellet seating tool that is needed.
I've not seen the tool.
I seat my pellets otherwise they fall out of the mag when you shoot.
Yours is in exceptional condition so £400 plus.