I'm pretty sure I have everything installed right, but when I go to pay for a ticket as a test, the screen that should show the payment info (price, total and such) is largely blank, and the total box shows 0.00, even though the cost should be $20 (here's a picture as an example of what I'm seeing: imgur.com/UIOvT.jpg).

I don't see any php errors, though there are warnings for some deprecated date calls, but they shouldn't matter. I've been banging my head on the desk trying to figure this out, it's the last thing before I can take the site live. If anyone has any ideas, I'd really appreciate it.

Never mind on this, didn't know about the tickets area, must be new since the last time I used it.

Yep - brand new

The important things to know are:
- You can specify when a ticket can be purchased (valid from / valid to). so you can make a cheaper ticket for people which book early, for example
- When you make volume discount, if you enter '0' in the 'To' field, that translates as "unlimited".
So you can for example have discounts:
From 1 - 5: USD 10
From 6 - 10: USD 8
From 11 - Unlimited ('0'): USD 6

- You can sell any other arbitrary item (e.g. have them pre-order drinks). For those items (which I call "Addons"), just set the "is Ticket" option to "No".

If you want to see some nice examples log on at http://demo.mylansite.org/administrator/.

Let me know if you have more questions.