50% off, perhaps, if comparing it to rediculous pet store pricing. But once you become accustomed to non-pet store prices the deals aren't necessarily as astonishing. There will definitely be some vendors who have good prices on stuff and there are those "deals of the day" to be found, but they're not bargain basement prices.

Most vendors only accept cash. Only two or three that I've ever noticed take anything but. Most just simply aren't equipped for it and it makes no sense economically.

Lines vary depending on the time of day. It's usually longest first thing in the morning, but there are sporadic rushes throughout the day.

I personally wouldn't expect this expo to be huge. Most vendors are saving a lot of their good stuff for the first Canadian Reptile Breeder's Expo in September. But you'll likely see a lot of babies of nearly everything and some left overs from last year.