On a cost per acre basis, I don’t know of anything cheaper than Indar and Propiconazole.
Captan is the next cheapest. It runs something like $20/acre. I think Indar is closer to $15/acre. As you know, propiconazole is even cheaper.
I tank mix propiconazole with a 1/2 rate of captan for very good control, at a very reasonable cost.