In general, if I invite you, either to the range or to dinner or on vacation, you are my guest and I expect to foot the bill.
Most of the people I take shooting are noobs. My son asked me how many people I have introduced to shooting through the years and took for their first range trip. We started counting, and when I got to 35 he helped me remember a few more and we figure about 43 newbies we have introduced to shooting. Of that number at least 30 have gone on to get their LTC.
It is very rare that I go to the range with a friend that is also a shooter. Most of my range trips are purpose driven. Training with a carry gun, finding out if a gun likes specific ammo, making sure a rifle is still zeroed, etc. I prefer to do that on my own and am really not there to socialize. Besides, a gun range is a lousy place to have a conversation.
If at the range, someone asks me if I want to try their gun, or shoot it to offer an opinion, I will shoot one magazine only. If I have that caliber with me, I will reload the magazine.
I really do not worry about round count through my guns. I bought them to shoot them, and if I like a gun so much that I shoot the barrel out of it, it warrants replacement.
I guess the only exception is my S&W model 29. Everyone wants to shoot Dirty Harry's gun. But I will usually only bring a box of 44 magnum, but a bunch of 44 special. Most people just want to shoot one cylinder of 44 mag any way, just so they can say they did.
The thing that bothers me about your first friend is that if you are truly friends, he knows you situation and puts you in an uncomfortable spot. Not the best friend to go shooting with. I mean, who does that? And not just at the range. If someone asks you to come to a cookout, the first thing you ask is "what can I bring?" and if they insist you bring nothing, you still don't show up empty handed. You bring some beer of something.
If friend 1 is someone you enjoy shooting with, for whatever reason, be proactive and the next time he asks if you want to hit the range say something like, " Sure, you bring some 9mm and I will bring some 45." Or if it's
@Broc Tuah tell him to bring .40.