Just wanted to give a shout out to Ace Gas & Supply here in Colorado.
Full disclaimer: I don’t work for them and am not affiliated in any way with the exception I purchase their goods and services for my lab.
We switched from Airgas 3-4 months ago and its been an absolute pleasure. We were getting all gloves, dry ice, butane and nitrogen from Airgas. Saved a ton of money so far, and have been able to consolidate our media purchases along with Butane, nitrogen, dry ice, and gloves. They offered us 30 day terms and deliver. And I personally appreciate that they’ve been willing to drive from Denver to Pueblo for emergency butane or media drops several times, the owner actually personally chose to try and drive down some emergency media during our last blizzard, he only made it half way, but the effort meant quite a lot to us.
Shout to my rep EJ for always crushing it and keeping the orders tight 
We were also stoked Ace Gas offers 50Lb stainless tanks which are your personal tanks they only go to and from your lab, no sharing. Been incredibly convenient compared to lugging the 100 lb tanks, my techs have been appreciative lol.
I’ve been through half a dozen gas vendors over the last 10 years, tried folks from all over the country and this is by far the best experience I’ve had. Competent customer service and competitive cost is becoming exceptionally rare IME. I don’t know if they’re on here or not Just thought I’d share some gratitude and hopefully help anybody who’s currently looking for a gas supplier in Colorado.