Strategy to find the optimal pricing for the course

I am trying to find out the best pricing for my course. I have been on Udemy for a little more than 2 months and Initially I priced it at $89.99. No one bought it unless there was a sale by Udemy. So, I figured I might as well set to the lowest price $19.99 and sure enough I saw at least one a day sale (during non sale days) at that price. Now my strategy is to just increase the cost by $5 dollars every month and see how that affects the sale. Does that sound like a good strategy ?

I am just curious to know what other strategies instructors are using out there to price their course correctly ? Any help is appreciated !