That is the hose to get, a stretchy one that expands to 21'. But ouch, that price!
Ocassionally, someone sells a complete unit (usually the "portable" version which can be permanently installed) for about double that price, but usually triple. I got a spare like that so I have one if mine fails. The problem is some are over ten years old, mine is a 2014 model. So the question is, does it deteriorate with age and how much? Guess I'll find out someday.