I know this is an really a fresh post, but I thought I'd comment on it since I was in there on my trip and got home yesterday.
I'm not sure why you got charged that price. First time I went there I had to get out of the rain fast, had an expensive camera on me, unfortunateky I had a tout following me in and I had to to pay him so 500Bhat for first beer. Second was 120 I think. LD was as far as I remember 160.
Came back 2 days later, no rain so when the touts came at me just said no thnx and walked down to Spicy and got in and paid 120 for the first drink.
As for paying for the shows, they ARE free, however as someone else mentioned, they will walk around after the show with a basket asking for a tip. To me it's common sence to actually do tip them for the show, don't need to be much. I gave 20 baht tip per person in the show. They were 3 and it was kinda interesting.
I don't know if I should have tipped more or less, but the girl seemed happy with it so I guess it was ok. And face it its half a beer, not that much.
On a second note. There is a nice girl in there called Oi. Good girl, friendly. Pretty pissed at me since I didn't come back for her. Even more pissed at the girl that I ended up spending my vacation with. >.< And although pissed she was still polite when I saw her a few days later by chance. Might be worth to note if you like gogo bars and your in patong.