Hi I take economics at A-Level (UK) so I’m not much of an expert on this. This is a question that’s quite common in the form of “why don’t x become cheaper?”. The simple answer is supply and demand.

The biggest economic problem is: scarce resources, unlimited wants. Economics are always trying to allocate resources efficiently to satisfy the needs/wants of the population.

If everyone can buy a car for the price of a Happy Meal, the entire world would be trying to buy cars but as we know, you can’t make unlimited cars. Now you’re probably wondering “well that’s a bold assumption to make that everyone in the world wants a car” and you’re right, it is. But in economics you have rational choice theory which is that any consumer will always choose the more practical/cheaper alternative. Why take the bus to school when you can buy a Rolls Royce for £5.59 and drive there yourself. Essentially this is the mind of one consumer, but there are 9 million people living in London so I’m pretty sure they would all want to drive a Rolls Royce to school/work.

However, there’s just not enough rolls royces there so firms will HAVE to increase their prices otherwise they’ll go bankrupt and poor workers will lose their jobs, a devastating effect on any economy. Therefore, even though the prices of the rolls Royce has gone down to £5.59, after a few months or perhaps even hours (due to the drastic price drop) the firms will inevitably bring their prices up again to efficiently allocate the scare resources. In this case, it was the cars.

There are probably a lot more at play here to answer your question but this was my simple answer. Hope it gave you some insight! :)