You did misunderstand. The suggestion was to add an extra day to the base ticket for modest cost and then use that extra day to go to a park for a few hours on a different day. In other words, instead of buying a hopper for $300 which would allow you to go to one park for 8 hours and a second park for three hours, buy an extra day and go to one park for 8 hours on one day and go to the second park for three hours on the following day.
This is what we prefer. Most days we fill our time in a single park. We find ourselves wanting to hop maybe twice in a week. The cost isn't worth it. Instead we buy an extra day for just a couple of bucks. Of course, if you are staying at the GF, adding the extra day to the vacation eats up your savings. But staying offsite, it can still be cheaper to do 6 days with a basic than 5 days with hoppers.