I think ima hold off on this till I know what the UU+ entails. Learning more and getting better sounds like my kinda deal.
In fact, since you are browsing the website, and using it already and done almost 500 posts , ill give you a breakdown on what things cost. I work in IT, servers specifically, so im only estimating this here.
Server cost: Probably around $200USD a month (depending on setup)
Time Cost: Probably a crapload to maintain, spam detecting on forum, server upgrades, backups, mainenance etc
Domain cost: probably diddly, but its a yearly cost
Current Income: whatever they get donated currently and adverts - probably not covering costs.
So currently, they would probably be running at a loss, which they are paying for themselves, to provide you guys with the resources you are using free of charge.
If regular users paid the $5 , they could cover costs they have currently and not be out of pocket.
Currently those not donating are pretty much taking money out of their pocket