I recently bought a '3n1' welder, Needed bottles for MIG and TIG. Checked with the three places here, Matheson, AirGas and D&D (local indy)
To buy 125 bottles the prices were 300 to 400 per bottle.
To lease, per bottle, the local indy guy was 90 bucks a year! Matheson was 77 and AirGas 55.
Clearly, I went with AirGas.
The refill on Argon was 28.
C25 was similar
I'll keep looking for a deal on owner bottles but leasing for now.
A tip for general knowledge: The neck ring will usually have the vendor's name "Airgas" or similar forged or stamped around the neck ring.
The neck ring is the first thing the store guys look at to decide whether you own the bottle or whether its a bottle that they will service/swap.
This is the important bit:
"owner bottles" have nothing stamped, the ring is blank. They call them (locally) "slick ring" bottles. They immediately know this is a private ownership bottle and there's no argument about "oh, that's a Linde or big 3 or whatever company bottle and we dont service those". If you have a slick ring, they'll know it's private and they'll service it, or swap it. Importantly, if you have a slick ring and take it in to swap, *MAKE SURE that they swap with a SLICK RING back!
If they swap out a bottle with some company name on it, then the next time, you may run into difficulty or at the least, you may be restricted on who will service it.
Also, if you see bottles at a garage sale or whatever check the ring.
Also be aware that the bottles have a date somewhere when last tested. If the date is more than ten years AND the gas place actually LOOKS for it, they may refuse to service it or may add a test fee.