Generic is the English word for it. The brand name drugs have a limited time patent and they are supposed to help cover the initial research and development costs of bringing that drug to market.
I doubt that most people in the US know the local sales tax. Let alone any change that may occur due to laws changing or traveling. I'd like to see the out the door price listed but that throws the 99 cent game off retailers like. Also I don't shop very often but Aldi US is the only place I've seen the eink price displays, the rest still have paper.