I bought my canister from the welding shop and they just exchange it out with another one that's full for $15. The canister is a bit unsightly but I have a good hiding place for it. I had a hard time finding a smaller canister but they sold me the 20 lb. for $75 (filled) which seemed like a pretty good price to me at the time. The canister finally ran out of C02 the other day but it lasted for almost a year which surprised me.
When I move the tank to the living room, I will have to find a smaller tank to fit under the stand.