Here is a thread that has formula/recipe that should save you some money.
I feel it is a good idea to learn as much as you are able about plant stress before you decide how much and when to stress your plants.
For instance, there is more than one type of plant stress not just SAR, and there are things to think about like crosstalk ect.
Remember AN is in the business of making money not growing your best plants, at least in my opinion.
The only true way to know if the changes were positive or not is a proper side-by-side experiment with a control plant.
Anything less only leaves you with anecdotal evidence, which is kinda meaningless, scientifically speaking anyhow.