I recall Meet & Greets as an occasional gathering so that the BBS members could meet each other in person but no money was collected. My recollection is that most BBSes asked for donations but few actually charged. It may have been common for certain BBSes to charge but I avoided those.
One of Prodigy's "strengths" was that it had a nationwide network of local numbers so it's members didn't need to worry about long distance phone bills. It was one of the reasons that Prodigy got as big as it did.
I can understand that may have been your experience. However, there were BBS's that had hundreds of nodes. Usually they were in a leased building and a single modem, because you were running data, could end up costing hundreds of dollars a month. Add in hardware, software, other content (Which unlike the current Web, you couldn't just download, it had to be purchased), and running even a small board, could easily run into a few thousand a month. So yes, charging a few dollars was very common. And yes, there were plenty of free ones out there. You cannot even include corporate boards since they were paying for them and they had a budget. If a local SYSOP decided to connect his Board to Wildkat then it went even higher. Take a look at some old issues of Boardwatch.
Prodigy had POP's in major cities. They didnt reach out (Much) to suburbs and they didnt reach out to rural areas AT ALL. The numbers they offered to those areas were long distance and many carriers charged data fees for using those numbers, which could run into a couple of hundred dollars per month easily. Secondly, Prodigy's cost rose because the advertising failed and they started censoring big time. Then they put a limit on emails (30 per month and an addition 5 cents, then 10 cents for every email beyond 30). Prodigy launched an unlimited additional Free chatroom, thats all anyone was doing, it was costing Prodigy a ton of money in Telecom charges so Prodigy closed it, pizzing lots of subscribers off and causing them to lose LOTS of subscribers. Yes, if you lived in a highly populated area, you could dial into Prodigy locally, if not, you were dialing in long distance and usually paying additional data fees. For most people throughtout the US (Except those in major metropolitan areas) the cost to stay on Prodigy was high. At the same time Quantom cost a fortune as well and no one used it until Case changed the name to AOL and launched Chat Rooms, that was pretty much the death of Prodigy. But even AOL cost a fortune. Compuserve's WOW! forced them into an unlimited service package. I was on WOW! from the day they launched to the day they folded. I still dont know why they folded, they were definitely a contender for AOL's business. I would suspect it was the fact that although WOW! was the first to offer 20 bucks a month unlimited service, 100% of their numbers were toll free from anywhere and their GUI was excellent, well built and easy to use, when AOL launched their 20 bucks a month unlimited service and started adding tons of content, Compuserve just decided to go back to their primary source of revenue, business customers. I dont know, Compuserve never gave a reason as far as I can remember, they just announced they were dropping the service and it was gone.