When I went to a quilt retreat last April (flew 2000+ miles but took my machine) my sister--who lives there--and I coordinated rulers, books, etc. Mostly I asked if she had and was willing to share because it meant I did not have to pack extra. Worked out quite well and a bonus was that our DSIL who is not a crazy quilter like us, joined us and it was so much fun to show some of the 'tricks of the trade'.
At home, my machine--my rules--and that is set in stone. At class, I guess I have been lucky because no one has asked to borrow my rulers etc.