It's considered a deceptive and fraudulent practice to have a final liquidation sale when the firm is not really going out of business.
See, for example, the form required in TX (a state not known for heavy regulation compared to say, CA):
http://www.window.state.tx.us/taxinfo/taxforms/50-290.pdf [pdf]
§ 17.82. Prohibited Conduct (a) A person may not conduct a sale advertised with the phrase "going out of business," "closing out," "shutting doors forever," or "bankruptcy sale"; the word "foreclosure" or "bankruptcy"; or a similar phrase or word indicating that an enterprise is ceasing business unless the business is closing all of its operations in a county and in all of the counties immediately adjacent to that county and follows the procedures required by this subchapter. (b) A person may not fraudulently represent that the person is conducting a going out of business sale.
I remember the manager telling me we were making $30,000 a day during the week-long sale. I guess "going out of business" is good business, haha.
One that especially sticks out is when the Circuit City chain went under. I remember reading about how they brought in an outside company to handle the sales, and the first order of business was to raise all the prices on everything in the store. DVDs that they couldn't sale at $10 were suddenly flying off the shelves at $20 (don't remember the exact numbers).
It makes you realize what a fine line (which each person has to draw for themself) there is between clever marketing and slimy, manipulative tactics.
Is this manipulative? I wouldn't call it that, at least not more than any other retail tactic. Consumers have more price information available to them than ever before, yet they are still amazingly susceptible to the idea that they are getting a good deal, nevermind that the widget that they are saving 25% on costs half as much on Amazon. If using psychology as a sales tool is unethical, then the idea of advertisement and "sales" must be as well.
People's perception of prices can be really malleable, so it can pay off a lot to have a high price in a location where people will be expecting the price to be better than usual.