Just a thought. London has really, really good train links. Lots of people commute to central London from where I live in Mid-Sussex. Burgess Hill, Haywards Heath, Crawley and Horsham are all about half an hour from central London by train in the morning and rents are much cheaper-more than enough to justify the price of a monthly train ticket. This is probably also true of the commuter towns to the East and North of London too, but I can’t say for sure because I haven’t lived there. Bromley is quite a good place to live and is slightly cheaper because, although it’s a London Borough, it is technically in Kent. It is on the Tube line too or you can get a bus.
However, I totally understand if he does want to live in “The Smoke” for a bit as at his age it is an exciting place to be.