Propane tanks 10 years old, what is best choice ???

If you are a fulltimer or a long tripper the biggest problem is finding a place that recertifies. How much, if anything, is another matter.

Had one done in Canada where the charge was nominal along with the refill. Had another done in the US where I almost might as well have bought a new cylinder.

The usual goto place is Tractor Supply. Yes, they check most of the time but I know they have propane & they are usually easy access.