For those who live in/near Madison WI looking for gas...

[mbronkalla]

Airgas will swap tanks that were not purchased there (at least eh Brookfield WI one does). I started out with a new Al tank and they swapped to a "nice looking" Al tank. I subsequent swaps they have switched with steel (out of Al) and back with appropriate charges or credits as applicable. The thing I dont like about the steel tanks is the valve is unprotected and if it rolls around on the floor it can (and did ) open some on a turn. Quick pull over to close it.

 

[hansh]

2023 update:
Jefferson Fire filled my 5# tank today for $18.

Really nice staff and it took less than 5 minutes.

 

[cactusgarrett]

A+ Heler's is a very reliable option, too.

Current prices:
5 lb float test $30
5 lb fill for $14
10 lb fill for $16