I have a 1 acre pond that has been overrun with weeds in the attached photo. I have treated with Diquat and cutrine with limited results. Any advice would be appreciated.

In Texas it's known as slender spikerush, aka Eleocharis baldwinii.
Probably the best treatment is GALLEON, assuming your pond's water is static (no flow-through).

Dang it Kelly, you're good!!!

Kelly thanks for the identification. Is there any alternative that would provide some relief at a lower price than Galleon?

Turner, to quote my frequently used axiom, "The most expensive treatments are those that fail to provide the desired result". So, to answer your question, there isn't a lower cost treatment that will provide much, if any relief; at least not to my knowledge - otherwise I would've already suggested it.