House we bought was infested with larvae. One of the most disgusting things I ever saw. Didn't see the issue at viewings as the house was rammed with furniture. Had to stay at parents and fumigate. After 2 days I came in and ripped out every bit of carpet then deep vacuumed the floors. Never again.
Whatever you do, make sure it's not wool. We have found it impossible to get rid of moths.
A nice rubbery layer underneath will make any cheap carpet feel so much nicer.
For office bits, there's a transparent hard mat you can put over carpet for office chairs to roll on.