Much depends on all the things you’d like to sharpen. Probably the best system if you just want to sharpen wood turning tools. Not so great for other stuff. I’ve used and used to recommend them to wood turners but I actually bought the Axminster version instead. I bought it when it was on special offer (£399) so a similar price to the Sorby at the time. Not so cheap now though.
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It’s a good machine. Variable speed and forward and reverse are handy. It can also be used with all the jigs available for wet grinders like the Tormek as it has a movable 12mm support rod. The Sorby uses a fixed 1/2” rod.
The big advantage to belt grinders is the ability to very quickly switch from say a 60g belt for reshaping tools right up to an 800g belt for honing if required for things like carving tools.
As suggested these do come up second hand from time to time but watch out for scammers. There have been a few warnings on social media about Pro Edge sales. Good luck with whatever you decide.