On my last base, normal work bays were free, as was small tool usage, unless you broke something. If you used special bays, like hoists, or paint booth, there was a modest charge. You did have to make a reservation and they didn't take kindly to cars sitting in the storage area for a long time. I think 30 days was the maximum.

Rental time on things like engine hoists was a couple dollars.

You will find the auto hobby shop facilities and prices vary a lot from base to base.