How much do they cost?
The cost of an evening out obviously depends on the nature of the event. Basically you pay your own way, so when we go for meals the bill is divided so you pay for what you ate, rather than an even share. While this can lead to some complex calculations at the end of the evening it does mean your meal can be as cheap (or expensive) as you choose.
For ticketed events we'll usually collect money beforehand so the organiser can get seats all together and take advantage of any group rates. Be sure to tell him/her if you are entitled to any discounts.
At all social events we collect a 20p per head surcharge that goes into group funds.