GB Tampa Tourney September 15

are purple, browns and blacks usually grouped together? I'd like to
compete but as a new purple I'd stand little chance against a black belt.

with that attitude you better hang up your purple belt....

considering that my instructor can whip me while balancing his
checkbook, i'd say i'm being realistic

How new of a purple belt are you?

Two months.

Are purples, browns and blacks always grouped together in tournies?

They are often combined at smaller tournaments. I've even seen it where blue and purple are combined. Someone just told me about a master's division being 6 white belts and a brown (you can guess who won).

That said, at this tournament last year it was only purple belts and one brown belt, no black belts. Maybe there will be one this year (I think David Viera wanted to compete last year but stepped out because he didn't want to spoil the competition for lower belts.)

Last year, a purple belt won his division, beating a brown belt on the way, and the open division (all weights, all belts) was won by a blue belt.

I think it's worth it if you're wanting to build experience. I can see how worrying about fighting a black belt could get you psyched out but I don't think it's something to really worry about.

I helped run the tournament last year and Aesop's correct.  You should come and have a good time!