Help with period details, please!

I have a question for anyone who has studied Austen's historical period more deeply than I have . . . In the beginning of Northanger Abbey, Catherine and Mrs Allen go to a ball in Bath where they don't know anyone. I don't understand the logistics of what they are doing . . . if they don't know anyone, it means they weren't invited (?). But there is no sign of them paying for it, either (which would make it sort of a nightclub or Regency discotheque, shall we say!). Who would have hosted such an event? Would they have paid, but Austen not mention it because money matters are indelicate (hardly, she talks about what people are worth all the time). If there was no cost involved to the guests, who footed the bill? Inquiring minds want to know! (Where's that annotated edition when you need it?). Thanks in advance for your help.

The balls would be public, and you would purchase tickets. Austen had no need to mention that, as that fact would have been well-known to her readers. Look at this page for more info (scroll down about 1/4 page for the rules on subscriptions and admission to the assembly rooms).

After all, a contemporary author wouldn't bother to mention that his characters paid for their theatre, movie, opera tickets, unless, of course, that was important to the plot. It would simply be assumed that they had done so.

I don't have it with me, so I can't give the pages, but there's another good description of all this and how it worked in Jane Austen for Dummies. As are some others in this series, the book is really good despite its title.

Another helpful book is What Jane Austen Ate and Charles Dickens Knew by Daniel Pool.

I actually own What Jane Austen Ate and Charles Dickens Knew, but I don't know where it is right now. Besides, I knew you guys would be faster! I'll have to look for Jane Austen for Dummies. And thanks, Lilithcat--that explanation makes perfect sense.