.... One ungrateful little wench.
For hunts like that, where you're already there and someone asks you to help: I don't think any of us would ask for a payment, or reward, or tip . Unless we'd driven there by appointment, and the cost was agreed-to ahead of time.
But you're right, AT LEAST they should give a thankyou.
That happened to a buddy of mine. He was working a very good set of scallops, down on the wet, when someone came asking for help to find a ring. And it was way down the beach from where his hot-spot action was. He agreed, and started the long trek down the beach to some dry sand volley courts. Not an easy feat, as he was well into his 70s, age-wise, at this time.
The bunch of college kids resumed playing volleyball, while my friend methodically combed the suspected area. Finally he found it. Held it up and called out to the guy. He came over, grabbed, said "cool", and ran back to resume playing volleyball. THAT WAS IT, eh ? Not even a thankyou ?
He hiked back down to the beach to his erosion spot, only to see the tide had now come in and covered it. He could have been there the whole time in his action. So ... yes .... in those cases, $$ is not the issue. It's gratitude for the time someone detours to help, should at least get a thankyou.