A Beginner’s Guide to Home Remodeling Costs - Here's a great infograph that show the variety and cost of home improvements that can add value to your home. Great article from luke1428.com by Brian Fourman
This is only true in theory, because of seams the way carpet has to run. You might add about 15% to this to get a rough idea, but carpet laying involves where you want the seams to be other things that should be discussed during the purchase time, not the day of installation!
The Bacri-Clark Kerman Sickle-Leaf Throne Carpet. Kerman, South Persia, second half of the sixteenth century, 1.95m x 2.65m (6ft 5in x 8ft 8in), wool pile on a cotton and silk foundation. Sotheby’s New York, 5 June 2013, lot 12. Estimate $5,000,000-$7,000,000, sold for $33,765,000