So, you want to F.I.R.E- where is the best place to do this? Well, if you know about F.I.R.E you know its all about savings rates. So- you need to both high earnings- but also low spending/outgoing. If it was all about earnings- then London, or Dubai etc that would be where all the F.I.R.E people would be living. But, its not all about earnings though- property in London is the highest in the whole of the UK- so ……
You need to go for a balance- of earnings and property prices (either renting or buying). The stereo-typical, just buy “up north”, might work for you- if you don’t mind living up there (and there is nothing wrong with up north at all).
The average house price in London is: £640,000 
The average house price in Manchester is £199,000 
The average salary in London is £34,000 
The average salary in Manchester is £28,000 
The earnings to house price ratio in London is a huge 18.8x salary to house price. Manchester by comparison is “just” 7.1x salary to house price. So, by using these figures- it would be much easier to buy in Manchester compared to London. This much might be obvious to most people- since London is so expensive- but did you think the average salary in Manchester was so high? Perhaps less obvious.
Do note that most banks won’t lend more than 4-4.5x salary, so even with a 10% deposit, you would need way more money down- or salary to purchase an average house. Of course, averages are just averages- there are houses for much cheaper than the average- and salaries both below and above these averages.
That brings us to Cardiff- average house price of £242,000  with average salary of £27,000  giving a 9.0x- slightly higher than Manchester. But, I don’t think this really tells the full story- Cardiff itself is a pretty small city (especially for a capitol one)- with just over 300,000 population. If you live just 15/20 minute drive/train away, for example up any of the valleys- the average house price drops considerably. You can pick up a 2/3 bedroom house for well under £150,000- but keeping the Cardiff salary. Yes- you can do this in London, but the commute time isn’t going to be 15/20minutes, its going to be at least an hour, each way. Even with that- I still bet you can’t find a 2 bed house under £200k odd (excluding shared ownership/flats etc)
That’s without talking about the public transport options of getting into Cardiff – new trains coming very soon, small amounts of traffic (compared to London). On the weekends- you can be in a nation park within an hour (Brecon Beacons)- or the beach in 30 minutes (Penarth etc). I maybe very biased, but Cardiff seems a great place to F.I.R.E