I just bought one of these 'life extended' tanks from PA yesterday for $400. I wanted something bigger than what I already had, and this should fit the bill with 8 years of usable life left. And comes complete with valve and fill whip.
https://www.pyramydair.com/product/air-venturi-le-carbon-fiber-air-tank-4500-psi-88-cu-ft-dom-2000?a=7995
Ok, more questions on air tanks. Since I bought my Texan, my need for air has really increased, and I’m shocked at the tank prices. I have a GX CS3, and it’s great, but I would like to shoot without filling after 1 or 2 shots sometimes. I notice my local dive shop will sell me a used 100 cf steel Scuba tank with valve for $250. Other than the weight, why couldn’t I do that? It says it comes with a valve, what do I need to add to be able to use it? Thanks.