i was in the process of changing the wheels anyway from 16inch to either 17 (official ones) or the veloster sport ones (18s) but wasnt sure which size to go far, that'll be about £900 to start with. I suppose I wasnt really bothered about leather anyway (cold in winter, hot in summer!) and the other changes to the spec are just cosmetic i suppose.
To satisfy your curiosity, why not go back to the dealership and get a change-over price and then you'll at least know where you stand.
I think you'll find that you're better off with what you've got given that you've owned it from new and only done 5,000 miles.
I don't know what it's like over there, but in Australia my experience has actually been the opposite with regards to leather.
After the initial shock of getting into a cold or a hot car and sitting on the seats, I find that good quality leather is the opposite of vinyl and is cool in summer (better than cloth) and warm in winter.
