The problem here is that everyone's view of "reasonable" is going to vary.

If someone trade a chip worth $5 for a chip worth $4 and wants $1 cash I dont think anyone would argue.
If someone trades a pile of chips worth $5,000 for a pile worth $4,900 and wants $100 then it is a small amount in terms of the transaction, but is it reasonable?

Yes, on the occasion referred to, which was my second convention (I only made it for 3 hours at my first!) I guess I thought it was the norm. There were people sitting on the floor outside with stuff scattered everywhere until you 'intervened'. I believe I was actually 'brokering' a chip between two others. A Silver Palace. And the only reason I remember is that someone on this BB uses the chip as their profile pic.