I need a report for an event on Civi that lists how many guests bought tickets at the different levels we had our tickets for sale at. How can I do that? I can't figure out if it's possible with any of the 4 default reports Civi offers for events.
You will want to use: https://civicrm.org/extensions/extended-reports extension - it gives you access to many more templates - including price set - line item ones.
we are using a 3rd party PHP-based reporting tool which lets us get reports based on SQL queries on the civicrm database - the native Civi reports are template-based and more brittle IMO. You could run the event participants list, export the results to .csv and then sort the resulting rows by participant fee, or net amount after pulling the .csv into Excel. HTH