Just bought an 8" titan brand bench grinder for under £40 from screwfix and it's a really good but of kit for the money.
I really can't say a bad word about it and I bought it on the online reviews.
look out for a 2nd hand old wolf or simular on ebay most if not all bench grinders made today have nasty pressed tool rests that flex cant beet a good cast tool rest
Got an Ajax 3 phase one small but powerful & an Old Sealey 8 inch paid £3 at auto jumble spent £10 on new bearings good tool use it most days wire brush on one end wheel on other all cast no tin in it.
If yours vibes on spin up are the wheels true & balanced