Not sure of the size, but £175 for 4 "good - to new condition" alloy wheels is a very reasonable price. Depends on condition of course.. and how much kerbing which could cause permanent vibration, etc.
If they come with tyres that have 3+ mm tread, then it's even better value.
I paid £135 + postage for 4 brand new 15" 3 spoke alloys (dealer stock clearance on E-bay). But that was a bargain!
They were fitted to my 1994 car, and are quite common in the UK. I think they were fitted for a few years. I do not know about 225 tyres. I think Scaero has 225 tyres, but on 16" wheels, and I think there were comments about them rubbing. Perhaps someone else can help.