This depends on your locale and the companies involved, and may depend on state regulations. In this area there are a couple/ three companies who "universally" will EXCHANGE Owner tanks, IE the popular 80 Oxy and matching Acet, 10, 15, 20 Lb CO2, etc.
My tanks were originally bought through CENEX/ COOP about 1975. Then they were traded for the co. I worked for, then I went to work for "Brack Supply" in Coeur d Alene, and traded with them, THEN went to ??? and that eventually was bought out and become OxArc. I have been lucky, never had a tank with an expired hydro-test, and other than the "price of the gas" I have never paid a DIME for rental, lease, or anything else.
Only extra cost was when I traded/ upgraded, as I mentioned earlier.