This is a reverse side of "best prices". So, to be more exact, such shops could have the following slogan at their doors: "We sell goods you need at best prices, but each buyer is offered a service what the most of our visitors is ready to pay". Many shops cannot efford an erudite stuff, otherwise they will be ruined.
But think this situation is not yet the worst because your sellers still may sell a quality product. Here we came even further: it's not possible to sell a quality product at a fair price because the market is driven by prices only and too often at the expense of quality. This comes from buyers poverty followed by lack of ideas about of consequences and sellers' cupidity. Buyers wants everything cheap and sellers meet this demand: some doubtful quality oils manufactured by order at blenders and a huge number of counterfeit spare parts. Price, price and only price. That's why, a piece of junk, very often unsafe, offered 15-20 % cheaper than a premium quality product is sold quickly, but a quality product needs time to find its buyer. This is a very big headache for foreign companies. The majority of counterfeits come here mainly from China, Middle East and Turkey, so I would "thank" namely these countries for their "great" contribution to the development of world ecomomy and our prosperity.