price variations
Rainyday, you have raised an interesting point.
Say most retailers of a product or service were selling at the same price. Is this:
(a) the effects of strong competition between them forcing them to sell at the lowest price
OR
(B) them acting as a cartel, and fixing the price higher to suit their own profits
Sometimes, it's difficult to know.
Also, as you say, price variation is a feature of a perfectly healthy, dynamic economy.
Late night convenience stores charge more, German deep-discounters charge less. The main thing is that people have plenty of choice.