Even with the price as it is, demand always outstrips the supply for TD. There are close to 800 TD events, and I'm sure they'll mostly fill up within the first few hours, if not faster.
At least this year the increase wasn't too bad. IIRC, 2 years ago it was $62, then went up to $78 last year. So $2 isn't much.
Whether it's worth it or not, well, that's a judgement call. I don't do TD due to a bad knee, but my friends have done it for years & they always do at least 2 of the full sessions. They've had a few bad experiences, but overall they really enjoy it.
ETA: As aaron points out below, it really is something you should at least try once. You do it, and you might come out of it with a few different opinions:
Boy, was that a waste of $80.
Meh, not bad, but not worth doing again.
That was fun, will definitely do a session or two next year.
That was freakin' awesome.. I'm going to start following TD from con-to-con around the country (like a Grateful Dead groupie in their VW bus), and blow all my disposable income on tokens!