bitcoin has value because now the total supply of bitcoin is very limited and also the demand of bitcoin is very high, now bitcoin can be used for multipurpose payment very efficient. that's a bit of an idea why bitcoin has a high value and price.
Scarcity is indeed a reason, but that is not the only one though. You can say that bitcoins are priced this way because people see it as something valuable and useful. Similar to gold, people value it based on how much they believe its value to be. To be honest, I would say that gold is a lot more useless than bitcoins as the latter is much much more malleable and has more real world use than gold which is just used as a jewelry or some sort of status symbol.