Worse choice is to use the exchange program. (Blue Rhino, etc.) Often you get 'short fills' and it's always more expensive than having existing tanks refilled.
Easiest would be to pay a truck to come in and do refills for you. Least expensive but more work would be to take 20's to a propane fill outfit yourself.
"If we couldn't laugh we would all go insane."
Arctic Fox 25Y
GMC Duramax
Blue Ox SwayPro