To everyone who hasn’t taken a macroeconomics course before:
When there’s more money being printed but no more goods being produced in an economy, the CPI increases and as a result you need to pay more for that good. For example, today the going price of an cookie is $3 and there’s only $300 to go around. That means that cookie is worth 1/100th of the entire market. Now lets say the government decides it’s too poor and prints out $300 and spends it. That means the economy has $600 and in order for the cookie to still be 1/100th of the entire market, the price would need to rise to $6.
There’s also the supply and demand of the cookie, but for our purposes we will assume that supply remains constant, and demand rises. Lets say we have a $3 cookie with only $300 to go around for everybody. If there’s only 10 cookies and 10 people in the society, then everyone gets their cookie and everyone’s happy. If there’s 20 people in the society however, then there’s not enough cookies for everyone. In this case, people will outbid each other in order to buy that cookie which drives the prices up.
Finally, let’s assume cookies are a necessity to live. This both drives demand up and at some point the cookie sellers will think “Hey, if I increase the prices of my cookie people will still have to buy it because they need it”. They can increase the price to whatever they want, as long as people can afford it, which further drives prices up.
Now given these three examples, prices of limited commodities work just like cookies. Let’s take PLEX for example. Lots of isk is being injected into the economy through b̶o̶t̶s̶ krabs, the playerbase expanded greatly with the introduction of alphas and now many people require plex to keep their L4 missions and rorq/supers running. This increases the CPI of eve’s economy, and as a result we pay more for PLEX.
Of course, all of these are based on the assumption that the supply of PLEX isn’t decreasing, and by supply I mean the amount of PLEX bought daily. As well, market manipulation and artificial inflation were excluded from this because while I personally believe the current PLEX market is artificially inflated slightly I don’t really feel like explaining what it is and what it means. Go take your own macro/micro course