Exactly so.
Last I knew, the price of 11-52-0 was nearly $1200/ton in Nevada. Super-phos (phosphoric acid, which was about net 50% P), as a little cheaper, but not much.
Nitrate fertilizers go up/down with the price of natural gas to some extent, but the phosphates went up and stayed up. The only thing that will bring them down is demand destruction.
I believe the Obama administration intends to repeal the law of supply and demand.