Our team has been working over the years to establish a 501c in support of our team. Right now, we’re investigating getting a bit more of a ‘workshop’ space, as our host school is packed, and there’s nowhere to really establish a workshop. I know some other teams are operating outside of a school, and one thing that occurred to me as a potential setback is needing some form of liability insurance. Do any of you have any experience with this, any recommended outlets or estimated prices?
You might want to consider 4-H. You can get more info through the 4-H Alabama Cooperative Extension Office (administered by Alabama A&M and Auburn University).
If you go 4-H, volunteers (i.e. mentors registered as 4-H volunteers) have automatic liability insurance. Accident insurance can be purchased for students at an affordable rate.
http://www.aces.edu/pubs/docs/V/VOL-0004/VOL-0004.pdf
Wow, that’s really interesting! I didn’t know much about 4-H, and somehow I’ve always heard of it in terms of more agricultural clubs / groups. That’s really awesome. Thank you for the heads up on that! 
EDIT: I see the accident insurance rates there - I didn’t see if that’s a monthly or annual thing, though. Do you know / did I just miss it?
Edit to my edit: Nevermind, somehow I missed the word “annual”, duh, I’m dumb.
There are quite a few 4H FRC robotics programs, probably at least 5% or more in the US. It covers the insurance of both the students and mentors for off-campus-programs. It also manages the background checks on all registered adults. There are also more flexible financial controls for the 4H clubs compared to ASB or PTSA schools controlled funds.
If you search 4H on Blue Alliance you will see how many teams there are already.
Talk with your school, you may or may not need a separate insurance. Our liability insurance follows us. So, we are covered when you go to competitions. It’s not location specific. But, what you will likely need would be theft insurance. With our theft insurance, we’re covered only for theft of tools at our build location. My guess is that your school liability will follow you to your off-site build location, but theft insurance won’t.
Also, with a school & 501c3 combination team, make sure to keeps records of what the 501c3 owns versus what the school owns. A local school team is stopping their FRC program, and wanted to sell us some of their parts. So, we need to know if the school thinks they own the parts, or if the 501c3 owns them.
We use AIM for the insurance policy that covers our 501c3, but we mostly work out of our school, so when we are doing work at school or on a board approved field trip (like competitions) we are covered by our school districts insurance. Our extra coverage deals with the other stuff. For basic organizational coverage I think it is just about $300/yr. Other coverages would cost more, but contact an agent to get that info.
https://www.aim-companies.com/public/groups/group/index.html?cd=pta