Beyond Professional Defense Shampoo

The shampoo I use is Beyond Professional Defense Shampoo. It is expensive, so I occasionally buy the large size. It is great for oily scalps. Other shampoos irritate my scalp and make it itch even more, so I try to use this one as much as possible, but the price is truly exorbitant. My wife is fine with cheaper options, so I feel a bit guilty every time I buy it. Once a year, when they sell the large size, I buy two bottles then, and once they are finished, I alternate between this and another shampoo. It has so many benefits, so it would be great if the price just went down.