Event Registration - Require Payment
I see your price set has integer fields for each, presumably so someone can say 'i want 2 of this one and 5 of that one' but that presumably is not collecting you the data about each Participant. If that doesnt matter then yes, set each field to default to 0 (perhaps) and make each required. But if in registering multiple participants you want to know that John's ticket is $500 and Mary's is $2000 then I think you need a price set that is just pure radio buttons (and set as required) then when filling in the form they would enter number of participants, and hence fill in name and price for each one on subsequent windows. hope that is clear. can flesh out if not.