I am a board gamer only, I have no real interest in RPGs. Do you think this would be worthwhile regardless?
Absolutely! I've been to a couple of Dragonmeets now and they've been very enjoyable from a board-games-only point of view.
Are there normally a lot of board games getting played?
Lots of them, including demos of new games and playtests of possible new games.
Are there games for sale and are they cheaper than normal
There are lots of games for sale, some, especially new releases, may well be cheaper than online, plus there's usually a huge amount of second hand games too.
It's definitely worth the time IMO.