Wise decision. Unless it has original fabric in good condition or a proven and exceptional provenance, I'd say £8-10k would be top money at the moment.
Disclaimer: There are two sofas in my house. One doesn't belong to me, and the other is from IKEA.
My wife found one that have been re-upholstered (beautifully) on Instagram, and enquired about the price.
£12,500.
We did not buy.