Cheapest virus tests?

[MateoinLosAngeles]

Got this Miltonidium showing some signs of viral infection. It actually blooms great, but it's placed next to other Oncidiums and Zygopetalums. They all have the typical black spotting on the leaves, but its next-door neighbor has started to show some yellowing of the leaves, albeit in the oldest ones.

This one has diamond streaks with small circles, and I'm trying to decide whether to cut the sick leaves or throw it away.

If it tests positive, I would probably isolate the other Oncidium to see if there are any signs of infection spreading. If it tests negative, I'm sure this is some bacterial infection from being too hot and lacking air movement. Perhaps it is low nutrients, as I have been under-fertilizing this year.

Is there a cheaper service than agdia.com?