The technicians rant on the cheap is cheap discussion was that it is of lesser quality. Said it was not as pure and that residue will build up in the lines and fittings. I can't comment on this as fact but feel it is the only explanation for both valves to fail. I have only used my heat one night in the 3 years we have had the trailer, the stove has seen minimal use as most cooking is done outside, it's the side that was failing worst.
Some of the bigger suppliers are charging $25 for a canister fill, Costco is doing it for $12.