In the topic about mattresses, TH mentioned that these industries obscure their products: cell phones, healthcare and mattresses. This makes it very difficult to comparison shop. I would add some financial products to this list--like annuities.
Another problem in comparison shopping is when there are no agreed upon standards. It doesn't have to be government standards--they could be industry standards as well. For example, sleeping bags are always advertised as good down to a certain temperature. I think that is all BS. I have used sleeping bags rated at 0 degrees and 30 degrees and the 30 degree bag was warmer. I understand their are no uniform standards in the industry to determine comfort at certain temperatures.
Another problem in comparison shopping is when there are no agreed upon standards. It doesn't have to be government standards--they could be industry standards as well. For example, sleeping bags are always advertised as good down to a certain temperature. I think that is all BS. I have used sleeping bags rated at 0 degrees and 30 degrees and the 30 degree bag was warmer. I understand their are no uniform standards in the industry to determine comfort at certain temperatures.