So 2.5 years newer but higher mileage. FR+ has loads of kit such as Xenons, nav, auto lights and wipers etc. so £10k should be easy I'd imagine!
So you have got a nice car. It does the job you need it to, looks good, goes well and is largely reliable.
Because your mileage is high, you are worried about wear and tear, so decide to buy a worse car that is probably already worn and a 2nd car (for fun) that won't be as nice as the car you started with. You loose the nice car and end up with 2 worse cars.
There is no logic mate, you will only lose out. Run the leon into the ground, or swap it for something else when you are bored with it. Just don't try to save money by swapping cars, it never works.