There is a total availibility of 18.4 million Monero in the market, and out of that 16.7 million has already been mined, since the genesis of the cryptocurrency back in 2014.
Now as mentioned before, the limit of mining Monero is 18.4 million, 16.7 million of which has already been mined. It has been noticed that a more finite a resource is, the more valuable it becomes.
Similarly, it can be predicted that the more finite Monero will become as a cryptocurrency, the more likely it is for the prices of Monero to shoot up.
You can find detail info also here:
Monero Price PredictionNow Let me know what you guys think about it? Will Monero Reach $500 in 2019?
The economic principle is indeed as you explained. The higher the demand, the more expensive the price. Likewise with Monero, the rest of their supply is running low, the number of cryptocurrency users is increasing every day. Of course the price of coins will increase. But sometimes we are just a tiori, not taking advantage of the opportunities. A simple example is if we buy Bitcoin or any coin in 2018, then in 2019 we become part of a billionaire.