Are some supermarkets scamming the consumer?

Check the prices in the supermarket that's being rung up they may not be the price displayed on the shelf. At times they don't even have a posted price (illegal) and charge an inflated price.  When you bring the discrepancy to the cashiers attention they refuse to change it to the posted price.

Kashrus wise, should one rely on their repacked meat, poultry or anything else for that matter.