Paper towels that just don't add up!

I went to the Wal-Mart Supercenter to buy some paper towels today. It seemed like half the aisle was filled with Bounty paper towels. Since they are the quicker picker upper, I thought I could pick some up quick. Wrong. I guess I could have just grabbed the Bounty Basic single roll, but since I was "shopping," I had to do some comparisons, right? Well, it looks like Viva paper towels are $1.65/roll, so the Bounty Basic looks like a better buy. But if I only buy one roll, then I'll end up buying more before I know it. How are Bounty papertowels packaged? Kind of like this:

BIG (xtrasoft) - 6 rolls = 8 rolls
BIG (select-a-size) 12 rolls = 18 rolls
SUPER (select-a-size) 6 rolls (must be equal to 6 rolls)
MEGA - 6 rolls = 10 rolls
SUPERMEGA - 6 rolls = 12 rolls
HUGE (guaranteed to fit) - 2 rolls = 5 rolls

Paper towel math is something I'd never encountered in 20 years of education, and since there is no commonality between the roll sizes, it's pretty much a shot in the dark. I ended up using square footage, and bought the 6 SUPER rolls (select-a-size) for $9.97.

Let's see how long it takes for the GINORMOUS roll to show up...