Buying a leather sofa is a minefield because the price can vary so much.
I bought a leather set of sofas (3 seater + 2 seater + chair) and paid £4k for it around the early 1990s. The salesman told me it would last forever and I would only change when I got bored with it. Today it still looks like new and have no intention of changing it.
I was wandering around House of Fraser last week and they had sofas (3 seater chesterfield) for around £2k and it looked rubbish.
There are many grades of leather ranging from the thin stuff with colour sprayed onto it to the good old fashioned gentlemens club type of stuff which is virtually indestructible.
Mine came in on order from a Belgian company whose name I have long forgotten.
Also most sofa companies, whatever the price, have sales once or twice a year, so best to target something and bide your time.