halocline
Contributor
Used tanks are definitely the way to go if you want to save some money; steel tanks that are not wet-filled or otherwise abused will last basically forever. A shop refusing to fill an old LP72 that's current in hydro and vis is idiotic, but when idiots own the compressor, they make the rules. The only risk in buying used steel tanks is internal corrosion, and its a simple enough procedure to take the valve off and get some light inside to see. Its very easy to see corrosion if its present.