I once asked one of my cross dressing clients to pick up condoms on the way to mine as I had ran out. I somehow went through 20 condoms in the session I had previously with strap on. I was nowhere near a shop to get more and if I ventured out, I would have been late for my next session.
Told my client I'd take ?10 off the rate. He showed up with a pack of 2 condoms. Nearly laughed. Actually did laugh when he realises it meant his strap on action would be limited for the evening because of his dick move.
I get clients trying to haggle at times. I tell them to fuck off.