Honestly $15 - $20 per day is not a big deal!

Break it down per hour and it’s only a $1 - $2 per hour.

Heck I would pay $20 per day if the dealers got their tables for free or at a reduced fee (providing even more dealers at the convention).

To “steal” from an old Credit Card commercial:

Flight, hotel and food for 1 week - $600 - $1000
Price of the 3 day convention - $15 - $20
Being with friends, making new friends and enjoying the hobby – Priceless!