£50 for a suit? Are you serious? Most of my ties cost more than that
For off the rail suits on the high street, M&S is probably your best bet. Stay away from Next, River Island, Topman, Burton etc.. They will sell you a shocking looking excuse for a suit. It will be shiney, poor fitting, poorly constructed and just a waste of money. It'll also make you look like a mobile phone salesman.
If you want a decent suit, go to your nearest tailor. When peole hear the word tailor they get scared off at the thought of paying big bucks but you'd be very surprised at how reasonable their off the rail suits are priced and they usually throw in alterations for free. If you are feeling flush and are willing to spend 4 figures then look at getting a bespoke tailored suit. Nothing will match the fit or finish.
Definitely have a look at the nearest tailor, you'll get a lot more for your money and they need the business!