I'm keen to get hold of some Argon gas and am shocked by the price and by how many people claim no rental but then charge for rental under another name.
George those gas bottles are not cheap, they have to be safety checked pressure checked regular etc. so rental is a method for getting that money back. After all you wouldn't get a brand new ford focus for nothing as long as you paid for the fuel. Rental is a fact of life on those bottles my annual rental bill from BOC comes to over £500. its either rent the bottles or dont work and sign on the dole. Obviously im earning money from the gas and figure the rental into my labour costs, bit different if you are just having a play around for a bit of fun or a car repair. Dont forget you don't have to rent a bottle for a whole year, you can rent one have fun and when its empty take it back.
At around 200psi or more I can see your point. If one manages to retain a cylinder of Argon from some source, how risky is it to keep it in the shed or somewhere for 10 years + as long as it doesn't start rusting? I see some suppliers mention the return of a deposit after you take the cylinder back. What happens if you don't take it back and are prepared to forgo the deposit?