Those seedy furniture stores that have "going out of business" sales that seem to last for years, are often running the same scam. Grocery also stores do this, with their shoppers cards discounts.

Consumers are the other half of the problem though. At least some of the scummy tactics are psycological hacks to get around real irrational behaviors that actually work against both the consumer and the business. The rest are dark patterns meant to manipulate and coerce that work strictly for the business, consumers be damned. I'm not sure where the line is.

Side note: Even to this day, I still catch myself sometimes thinking/saying the cost of something is $X rather than $X+1, when the listing price of something is $X.99, and I curse myself for the foolishness :P