About the prices: not sure, but it would seem they did raise them. My first domain was cheaper than my renew last time around... which seems weird too.
About ending leagues and why: I'm just as fed up with inactivity and *****ing as you probably were, and I'd be lying if I said that wasn't partially why I always think about shutting down shop.
The money end of things is probably 70% the reason why, but that's factored in with the other stuff... in other words if everyone was 100% active and this thing was booming right now, the money would look like less of a waste each month. But as is right now, 17.95 per is too rich for my blood when I also have to pay gamefly each month and still don't work.
The league participation being lower definitely has to do with the site participation. There's always the mainstays in both the sim leagues and boards, but even longtime posters like Reefer have been vanishing lately. I can't even begin to name how many good GMs have come and gone from TPSL at this point (McKain, Fischer, Theo, Witlon), but it seems that when they leave it has coincided with them leaving the site or vanishing from the boards as well...