What type of Makerspace are you setting up? Full on shop?
Will you have any tools for breaking down larger stock? Will you be working with wood?
First aid kits
Will you have enough room to keep wood area separate from electronic area separate from machining area?
How many kids will be working at one time? Will you need multiples of some of the above items?
Is this on a college campus with young 20-somethings? Be prepared for anything not bolted down to somehow go missing from time to time. I’m not saying everyone is a thief, but I didn’t realize it until 4 years after I graduated that while we were packing up the lab we were in a solder sucker or two ended up in my personal items box that I don’t remember owning.
I would go with name-brand hardware with warranties. Call up the companies and tell them what you’re trying to do. A lot of times they’ll sell hardware to colleges at a discount, or even provide longer/better warranties and coverage on the products knowing that they’ll be abused.
See if there are any colleges or towns close by that have one setup already that you can see and ask questions about. Ask them what they would do different.
Does that $15k include operating costs or materials?
$15k can go a good ways to making a really nice shop, but it will take some planning and figuring out what direction you want to take it.
Regarding the MPCNC… if you go that route, it would probably hold up ok, but you’d be rebuilding it when parts broke. Have spare parts on hand and if you have room, have more than one setup. You’ll want to mount it in an enclosure for safety. Last thing you want is a kid sending a 1/16" end mill full depth through aluminum causing something to snap off and embed itself in someone.