When you come to PIB you have to remember everything will run a bit higher. There is the cost to have everything shipped over on the boat and it is a resort destination. But the cost of beer might be a little higher, however not much. So you have to figure out if you want to save a buck and lug it over yourself or just run down to one of the stores that sell it when you get there.
You are coming on a great weekend...the Webster's are playing as well as Mad Dog. So you won't have a want for good entertainment. Mad Dog is a must see, a two for one show...comedy and music. He only plays during the day though.
As for the bars, there is something for every one. And I would suggest hitting them all since you've never been there, that way you can see which ones will suit your tastes best. There is also a Winery on the island and it is always a good time too. Plus a lot of other things to do like wave runners, kayaks, parasailing, golf, bi-plane rides over the islands. I guess what I'm trying to say is...don't worry you'll have fun.