A similar issue comes up in other domains too. For example, St John Ambulance Australia provides first aid for public events. Most of the duties are covered by volunteer first aiders. However if they cannot meet demand (which is often the case with mid-week events where volunteers are otherwise engaged with their jobs) then there is a commercial arm which steps in to cover the event.

The problem is when you have commercial and volunteers together at the same event, and some volunteers may think:

  "Hey, screw this, why am I volunteering my time, when the guy next to me is getting paid a decent hourly wage to do exactly the same thing?"

Quora has some kind of pay-to-get-an-answer with credits. It’s a virtual currency on the website, and you can use them to ask someone to answer (you pay them a bunch of credits, they always get 25% of it, and can get the remaining 75% by answering the question). Unfortunately, the asked user can write a crappy answer and get all the credits ; and you can’t convert them in cash.

I answered $100, but I am thinking more about Stackoverflow.

But I am willing to pay for someone fix my problem, not answer it. I mean, get access to my code and solve the issue himself. Like a micro-freelance job.

Thar way there is still incentive to answer doubts for free, in order to get more points/karma and attract more clients/charge more money.

I am one of the lead Drupal developers and I do offer a service to get your Drupal.SE questions answered. So few people actually come to me with it. I am still answering questions for free. I do not see a problem there, really. But I guess because it's not officially supported.

There is a distinction between integrated and non-integrated payments. If you are offering it off the record, you are doing contract work at a rate you like.

If you provide payments integrated, typically the financial incentives become market dictated, and once money is involved the intrinsic rewards become greatly decreased.

This I support more than paying for bug fixes.