Hello Dave, from the top of my head i can only remember a few of the prices in Goa, but i do know they are very cheap.
When i was in Goa in Jan 2007 with my little boy, we spent all day at a beach shack in Baga, from 9am til around 5pm, and spent around 600ruppees, which is about 7 - 8 pounds.
We had breakfast each, lots of drinks - coke, fanta etc. Lunch each, more drinks, snacks eg crisp.
For a beer its about 50 ruppees, the average we would spend in one night for our evening meal including soft drinks for my son, and a few kings for me ( a few meaning around 8 haha)
We'd spend less than 15pounds altogether.
We our back in Goa in a week