It seems like if it did happen, we would hear about it from a former moderator, right? My guess is that it doesn't happen. I would think that organizations have too much to lose to play with that fire. kleinbl00 you have mentioned that you moderate a default sub, have you ever been approached by someone offering you money for favors in regards to that role?
I"ve never been approached. No one I know has been approached. Frankly, "have some money" is far more crass and far less successful than what works and what happens daily. qgyh2 became an admin to post Amazon referral links to pay for server time. He did this after a prominent power user (who shall remain unnamed) started a sock puppet named "AmazonAssociate" who would answer questions with Amazon affiliate links. Note that he had nothing to do with Amazon - and it doesn't take long to set up an affiliate page. Nonetheless, back when Reddit had like 80,000 users he was still making $200-$500 daily. So now affiliate links are banned unless an admin posts them. SolInvictus was totally for hire. Reddit accounts are readily available for sale; gold farming takes many forms. Without saying too much, I was moderating /r/politics when the blacklist came out. I left two days later. I'll let Napoleon Bonaparte speak for me: Never ascribe to malice that which is adequately explained by incompetence.
It'd be much easier to just use vote bots to get a similar effect anyway. I'm something like 90% sure that reddit's frequently manipulated by vote bots.