There's nothing wrong with charging high prices for things that are in high demand and low supply. That's what encourages more suppliers to enter the market. Th

There's nothing wrong with charging high prices for things that are in high demand and low supply. That's what encourages more suppliers to enter the market. There are two major situations that regulation needs to protect consumers from - asymmetric information and monopolies. Taxis are a major example of the former - that negotiating on the street would create traffic problems, and getting into the cab, then negotiating would create a major imbalance of power in the negotiation. An example of the latter would be if Uber was the only player in the transportation market (market share > some large %) and could charge what they want, and then said something like "the only way to book one of our vehicles is through our app, and you cannot build a system which lets you book either an Uber vehicle or non-Uber vehicle."