|laziness, impatience, and hubris|
I somehow doubt there would be a problem with that.
Take a look at the stats. There are a few thousand users who have logins to the site. About 2000 of those with writeups, many of which may have come and gone. About a thousand registered users had a login in the last week. Judging active site participation from putting in a tag for jcwren's bot, we have a couple of hundred real users. Many of whom are students or have been hit by current economic events.
If we are lucky we will have a few dozen people willing to support the site. Covering costs is a plausible aim. Covering costs and having enough left over to have a single full-time employee (ie vroom) working on the site would be a wonderful goal but I am dubious that it is viable. Considering how much real value is contributed to the Perl community, a corporate sponsorship might be possible. I have no idea who you would talk to about that. Various publishers perhaps?
When it comes to individual contributions, well perhaps multiple techniques would work. Personally it is easier for me to come up with money than time. (Particularly once you realize that I already spend a lot of time trying to contribute to the Monastery.) People without steady jobs at the moment are likely to find time cheaper to give. Those two could co-exist quite easily.
But the idea of trying to charge for services rendered, or to segregate things into paying members vs non-paying members turns my stomach. I don't know about others, but I have found at other sites that attempts to "reward" me for being there stifled conversation and made it a less rewarding experience for me. I really think that would ruin the dynamic that makes PerlMonks work.
Ditto while I would be willing to make a financial contribution, I don't like the idea of making a big deal out of who is paying and who is not paying. As I have said many times, I dislike cliques, and I am generally against things that I think will lead to cliquish behaviour...