However if you're not my friend, I have no reason to take financial risks for you however small.
Consider perhaps you are not good friends with these people.
Technically that's not true. In the cases of con men, social engineers, and manipulators "giving free stuff" is a common psychological tactic to gain leverage over others. I.e. the sub prime mortgage scam bubble of 2008.
Sometimes he tries to say, "Oh, since I got a pizza last week, you can pay for this Chinese food and we're even", and I have to tell them that it's harder to keep a running ledger in my head than to just go through every transaction once at the end of the month and ask, "Is this a 0%, 50%, or 100% expense?"
I have him pay via ACH into my dedicated 'incoming personal payments' checking account.