I haven't seen any large scale, long-term open source projects succeed with a 'pay to play' process; what usually happens is the original maintainers realize that even with some amount of compensation, they still don't like scratching other people's itch when it comes to their project.

And then they realize that the amount of people/companies even willing to pay at all is a tiny fraction of 1% of their potential target market.

The better advice is to do what you want, know your limits, consider sharing some maintainance responsibility with another committer or two, and don't ever feel obligated to do anything with other people's issues and PRs. It's nice to do, but if it's interfering with anything else, or taking away valuable time, ignore them or just blanket close them, with a note that it's not something you'd be interested in maintaining.

The great thing about open source is someone can fork your code and do what they need. You have no obligation to help them, it's just nice if you can. And if they don't get that, that's not your problem.