Here are packs 9-12 of my box of one of the late-90s better brands. (Still apologizing for the white space on the scans. No matter how I try to crop it, the new version won't save.)
Well, we're now halfway through this box. Based on the odds and number of cards, I expected to complete 93% of the set (if there are no dupes) and pull 4 inserts. At this point, I have pulled 3 inserts and have completed 46% of the base set. No dupes so far. We'll keep it rolling next time.