Generally I would say go all out, but the key factor here is co-angling in someone else's boat. It would really depend how much time you spend in there, how clean they are (including boat shape), how they drive, how much they respect your gear, etc.
I personally have $400+ rods, one thing I wouldn't do is entrust them with another owner bouncing around on uncovered decking with exposed materials, or taking hard hits from wakes/waves from inexperience, having them left out on the deck or unlocked for breaks/rest. Blah blah blah, you can do so much, but you're still a coangler and not in control.
Now this is all hypothetical, but I've seen it before and it does happen.