In our part of the country, estate sale items are often highly over priced. Part of that is because the estate sale operators are usually more savvy as to values for what they are selling. Another part of it is the large amount of traffic that estate sales get around here. The more people who pass by, the more chance of finding a sucker (er, buyer) at a higher price. Some people do not know it, but it is not uncommon for estate sale companies to sell a lot of their own company owned goods at the estate sale, sometimes a significant portion of the items at an estate sale. Because they have essentially free venues to sell their personal wares, they are not in a big hurry to liquidate them. So the prices rise... (I find many of the business models used by estate sale operators unethical.)
I have much better luck here with garage/yard/moving sales and with Craigslist. They can be awesome if you get up early and see what is new for sale out there, and then jump on it immediately. It really helps being retired.