In general, we try to cache as much as possible, so you'll get dinged less, overall. Viewing a case on PacerPro does not incur a PACER search fee. But re-syncing it will. Downloading a document will cost the normal fee, but once you've downloaded, you won't ever have to pay for a download. If anyone has downloaded the file, then everyone gets to view it for free.
Each time you run a search, you will always incur a PACER search fee. We save search results, so you can go back and continue your investigations. If you want to refresh or update the results, you'll have to run the search again.
The big cost that surprises people is the daily scheduled update. If PACER charges $3.00 for the docket report, you'll get a PACER charge of $3 every single day. If you do this for many cases, in can add up. e.g. 10 cases would cost you $30/day. Over a 90-day billing period, that's close to $3,000. You can dial down the frequency to every other day, or weekly. You have to balance the cost of the reports versus the benefits of up to date information.