I track Anker's prices often, I do not keep a spreadsheet but a mental memory of specific products I tend to want myself, or for others.
These screenshots are not realistic. They show a discount against a list price which was never. For example currently there is a a product you cannot buy as a price about 250% what it would typically expect to sell. I expect its price to drop soon to say $50 and as its "usual discount" then offers to make it in the $35-$40 region. To me, I would compare a $35-$40 against $50, I would not compare to $100.