This has been spoken about a few times in the past:
I'm yet to encounter a boat owner who's asked for an ongoing contribution - there have been times when I've offered to chip in after a breakage, especially if it was a f-up, I can't actually recall any request or someone taking me up on this offer and if I'm honest, for this, they've probably garnered my loyalty and devotion to work harder/better etc.
The usual contribution that I was brought up with, and therefore assumption as a crew member, was that you work your butt off a couple of times a year helping out with maintenance - so, haul-out, sanding, painting, cleaning etc,
On the other hand, I know the point at which the grandfather decided he'd had enough was when he'd given notice of the haul-out and next to no-one turned up - that was the end for them as a crew.
This has resulted in my factoring of boat ownership being that if I want to race, I assume the cost of campaigning is entirely my own. Buying a round at the end of the race is my way of saying thank you to the crew for helping me enjoy racing my boat. It's expensive campaigning, but there are people who want to race their boats and struggle to find crew.
Saying that, if all the crew bring in occasional contributions of booze and food as well as buying a round or two, this makes everyone happy (and well fed) As a result, I have as a crew member, many years benefited from free sailing and racing at a cost of up to $30 a week buying my round (depending on crew size)
I think this is a defining part of our sailing culture. I like it. It works. I'll still grumble when it comes time to anti-foul.