I understand, I know quite a few places that charge 100-150 pesos but they are not on the beach. Besides,I do like Capitalenos do, I come with a cooler and do it my own mixing, much more economical (just kidding !).
For regular tourists though, a mixed drink would be 400+ pesos where they are from (without the view), so they think they are getting a deal.
I thought the bar accepted rate in LT was RD125 for a cuba or santo libre and the same for a medium Presidente.....but did note that the prices started moving upwards at the back end of last year. Mojitos charged about that price for a medium Presidente when I was last there a couple of months back.
That beer price seemed universally accepted even when the 'fairs' came to town and at Punta Poppi when the makeshift bars were set up on holidays. Seems the rules have been trashed.