Varies by location. My local Airgas were great to me when I was an ignorant newbie, just as nice when I was buying eight grand/month in consumables and gas for my job, and equally helpful now I'm just getting stuff for myself again.
If any Airgas management read this, it appears your corporate practice could learn from the Sumter and Florence, SC locations.
No one mentioned price of used equipment and you should also watch out for rigs that used MAPP or other fuel gases. Though not as common as O/A the gauges and hoses are not always compatible with other fuels, look for T grade hose for multi-fuel use. Also tips are fuel specific but again O/A is the most common mix. Also two stage regulators are nice vice single stage. Less fluctuation in delivery pressure and volume with two stage. Look at the nuts at the cylinder connection. If they have been abused (are there teeth marks indicating that channelocks or a pipe wrench was used to tighten or loosen) what does that say for how the rest if the rig was maintained?
Look over every inch of hose for cracks or cuts, if you find any it worthless.
In the end I wonder if its really worth buying used. If you are just getting set up and will be using the equipment for years why not start with new? If new is out or your price range then you need to spend some time learning what to look for or take someone with you that knows what they are looking at. The consequences of inexperience and a malfunctioning equipment are scary.
The "gauges" use METAL Bourdon Tubes and not fuel-gas specific.
The REGULATORS may or may not be compatible but nearly all of them are and if in doubt, post here and unless they are some obscure brand we'll find out for you.
Victor, Smith, ESAB etc are compatible unless they are ancient. Full info is available on their websites so take my word for nothing.
Two-stage regs can be useful for delicate gas welding, but aren't necessary at all for cutting. Much delicate OA welding is done with single-stage regulators.
Twin stage are expensive so buying used and having them rebuilt if needed can be a good way to go. I don't bother since I don't have fluctuation problems (a long hose dampens small surges).
