So I throw in the 205-70-13 for my Pontiac Phoenix and the 205-55-16 my Grand Am and Cavalier take, and find Overall Diameter 24.29 in and 24.87 in. I am paying a premium for tires with a bigger hole in them. A rip off just like the cartridge filter element you pay a premium for a filter with no base plate, shell, ABDV, or bypass.
Well, you could just go buy large slabs or rubber by the pound at some recycling shop or straight from the manufacturer. I'm sure it would be even cheaper.
The idea behind low profile tires is that they're more stable at high speeds and provide quicker steering response. For that, the sidewalls have to be made appropriately strong. That's what you're paying extra for.
Actually, 205/55/16 is a rather common size these days and not that expensive. Look at prices of some of the 225/45/17, 225/40/18, or 235/35/19 tires for comparison.