Hobbyist publishes 20 of these each month - the other 76 wait. Pro removes the cap.
90hours back per year
Listing 96 cards a month by hand takes about 96 hours a year. Through CardList it takes 5.8 hours.
A tool that takes 2% of your sales would cost $553/year at your volume. CardList Pro is $239.88, whatever you sell.
Pro is $19.99 a month. It pays for itself if 7.5 hours of listing time a month are worth that to you.
Time saved assumes ~5 minutes per card manually vs ~18 seconds with CardList. The 2% comparison is a generic percentage-fee tool, not any specific competitor. Actual numbers vary, but they go in this direction.