Common etiquette situation

[goofball]

Doing someone you sort of know a favor and them wanting to give you a small amount of cash.

My neighbor kid knocks on my door and says could I help them out. I don't know these people but I say hi etc. when I pass them going in and out. It turns out they need me to drive him and his dad to where the wife is stranded with a flat tire abotu 4 miles away. We just start to change it when the tow truck she apparently called showed up and changed it. The spare looks very dubious so I follow them to walmart about a mile away in case their spare tire gives and plan to follow them home if walmart isn't open. They were and I was set to head home. Whole thine took about an hour or so, maybe slightly more. Before I took off the dad tried to give me $10 bucks. I almost always refuse these kinds of offers but today I was doubting my self for some reason. Thoughts?

More generally underwhat circumstances are we accepting money for these kinds of favors and when and how much are we offering? Not something worked out in advance just something you were offered at the end.
I usually accept a couple bucks from someone if I'm a) giving them a ride, b) might be doing it regularly, and c) they can't reciprocate.

This post feels kind of rambly but I feel uncomfortable in these kinds of situations.