I made it to the local (for me) Harbor Freight today, and indeed they had the carpet cutters and blades. And the price is 1.99 now here too.
Several cutters with blades were hanging on the racks, and I would have bought that if I had needed to, but they had 12 packages of 2 blades each hanging on a little hook, so I bought all of them.
Next we went to Jo-Ann's, Hobby Lobby, and Michael's, and wherever there were blades and cutters for sale, we looked at the prices.
DD and DS were gum-fuzzled at the prices quilter's have to pay for tools and equipments.
So it was a very good day in the neighborhood.