An 80% is actually almost double, I think what you calculated was a 20% increase. Still, somehow you managed to get close on a price per block. Except that you are buying at least two fabrics per block, so I would add more to that cost. And for a large quilt, I would have to add in long-arm costs.
But I take your point. I bought enough fabric last year to ride this out, and all I really want is to create. No dust on my machine this year.