Question for National Breweries

I would like to know how you do your pricing? as I attended the zim golf open this past weekend and was amazed to have to pay $2.50c for a pilsner beer? the retail price is $0.90 cents plus 170% higher. as the main sponsor to the tournament I would have thought your prices would be a lot less to promote the brand. I was not the only person complaining this was not a very cleaver idea.i will not attend again or will bring my own beer.
I would appeericate your responce