We had quite a lot of fun last time and I've often thought about planning another, but just never made the time.
The only difference this time is that the store now charges a $2 per person fee to use tables, but that's good for the whole day and if you buy $20 or more worth of merch, your fee is waived. So not a terrible deal, really, and I would still want to support the store.
Depending who planned to attend, I would try to make sure there was both a "hardcore crush the competition no newbies allowed" table AND a "just for the fun of it, games may start slowly as rules are patiently explained to newbies" table. I tend to see a desire for both at any event where there's gaming.