Oxygen and Acetylene tanks

Finally, finally got a torch setup with cart the other day, no tanks.

What's the best way to get the oxygen and Acetylene tanks?

Buy the tanks and pay to have them filled?

Lease the tanks and have them filled? I'm assuming you pay the lease and pay to fill, but leasing must be cheaper than buying?

I would think a set of tanks would last a hobbyist like me quite awhile.

Suggestions I've gotten are: Airgas, Mississippi Welders Supply, Advance Auto Parts. And I see Fleet farm has an exchange program, just like propane?

Thanks in advance.

buy 

Never every buy large commercial size tanks w/o a title from a gas company. No one will fill them for you without it.

Some gas companies will even give you grief refilling small bottles w/o purchase documentation from a gas company.

I own and exchange mine through Matheson. They gave me grief over the acetylene recently as there was no label on the tank to identify gas type even though I have titles. Would not refill.
I would check with your supplier of choice and get the rules first before deciding which route to take.

Thanks for all the replies. Between what I read here, and talking to a co-worker, I think propane is definitely the way to go. Working on all this old farm equipment, I only ever heat and cut, I'm not much for brazing.

Think I'll swing by Mississippi Welders and see what they have for oxygen tanks.

You need a different cutting tip if you run propane?

Why can't you braze with propane?

Thanks.

I think I now have 12 tanks that I own - son has 3 or 4 of his own - Had 3 different suppliers I was using but now Mississippi Welding does all the filling and testing on mine and My NAME is painted onto tanks so exchange my own . 
 One outfit I bought my tanks from started sending me a bill for a testing charge each year even though they exchanged tanks when filling - bring in mine and they would just take a filled tank and exchange with mine . 
 Propylene or MAP gas costs less than Acetylene now but requires a different tip on cutting torch (propane tip). I use mostly propane as seldom gas weld any more - in fact with TIG welder it's more controlled .
 I converted several old CO2 fire bottle valves over to storage for oxygen, Argon, Tri-Gas so have a supply if and when I move welder without moving the 312/322 capacity bottles around . 
 Neighbor use to cut old rail cars up and he would go through 20 or so 322 bottles of oxygen a week - I got bottles from him and made a jumper hose to refill my 122 bottles from large ones as he paid $5 a bottle for content .
 Mississippi I believe charged $12 to recertify and test bottles and is a 5 year date stamp. 

I bought my tanks years ago from the local NAPA store . when it goes dry, I simply take it back and they exchange it for a full tank. Paperwork is in the fileing cabinet.

Well, here's what I come up with on tanks. A quick search for used tanks turned up nothing.

here I own a set of oxy and acty tanks, Praxair is the main Co. that fills them, there are dealers around(mostly welding, hardware type stores), all i do is take my owned empty bottles in and exchange for full ones for cost of the gas,, they prolly have a surcharge or something to cover bottle tests...oh yea,, I also lease a set for the portable welder,,, but kinda the same thing,, exchange empty for full,, but gotta yearly bill from Praxair, its like $120 for actyand oxy + a bottle for the mig...

I haven't gone to MVW now for a few years, as I loaned my setup to my son.....I'll have to ask him about it and get it back.