Is $6.74 a good deal for 1 gallon of Ultra Fine Perlite?

It's exxactly $6.75 down to the penny. THe perlite is Ultra Fine for superior moisture control. Is this a good deal? It's the cheapest I could find for that volume of perlite.

I'm a dirt farmer and I use the expanded perlite, the bigger the better. I use it for soil aeration not moisture control. You might not want the ultra fine but then again maybe you do.