Yep, 300 quid sounds much more like what the price should be.
Do you shoot many film types? If you do, I would strongly recommend having a couple of backs handy so that you can change film type mid-roll. I typically carry 2 or 3 on an outing: B&W, C41 and maybe IR, each in its own back. I haven't looked lately, but good-condition backs should be well under $100 each so it's worth thinking about once you're comfortable with the camera. It's particularly nice when shooting portraits; you can shoot a couple in B&W then a couple in colour and switch back & forth at your leisure. And you can have a stack of pre-loaded backs ready to go so that you're not spending all your time loading the camera.