The dinner or "banquet" I think is over-rated, you can get a nice meal in the restaurant for less money or a bar meal for even less.
By memory.
banquet, £24 for one, two or three courses.
restaurant, £14 for one course, (nice grub), then a bit more for starters or a pudding or both.
bar meal, £10.
These are last years prices, by memory so could be a bit out, but it gives you a feel.
Haddock.