Reefcrystals and Regular IO salt price go up and down through out the year, it is like that for the past decade. The wholesale price is pretty stable though. It is a lot to do with individual online retailers and shipping cost is a factor. Also the competition among Amazon, Petco, Chewy. Beware that some lower priced salt are actually close to expiration. There may not be an expiration data on the buckets/boxes, but retailers track that.
