I consider True Dungeon to be a "Bucket List" event. Everyone should do it at least once. Yes, it's expensive, but 2hr concerts for Hootie & The Blowfish go for $225. Heck... IIRC Elton John tickets were over $5k each (and that was for a 3hr concert). So, $80 for two hours or more is not that bad really.
I would underscore this, as it summarizes my thoughts. It is expensive, but memorable. And, it might not even be too expensive compared to other 'events' like a musical concert, horseback riding, etc. Likely, by the end of the convention, it will be prominent in your memories.
However, you should do the event that is a repeat from last year. It is $58 instead of $80. It is essentially "sealed deck" in that you only get the random set of tokens they hand you. You cannot bring in outside tokens. In my opinion, this is actually a feature, rather than a bug. Above, a person complained about getting stuck with people who spent a lot of money on tokens in the store and asked them to "hang back". Lol. Nope, I'm not doing that. This person apparently got stuck with jerks -- but that is a risk at any Convention event. You're less likely to get these people at the $58 repeat event.