No this game isn’t costly at all. There a bunch of free aircrafts that are really good, if no the same quality of paid ones. Some of them are the Boeing 747-400, the Boieng 737-700, or the Airbus A321.
We should be glad that the devs even gave us free aircrafts. X-plane 10 only gives you one aircraft for free which by the way is the defailt aircraft and the rest you have to pay.
Some of the regions in this game are also free and just like the aircrafts, some of the free regions are really good, if not the same quality as the paid regions. SoCal is an example.
As for the multiplayer, it isn’t cheap, at least the yearly subscription ($50). But, if we do the math, the devs are actually helping us save money if we buy the yearly subscription. There are a total of 18 paid aircrafts and 7 paid regions. Let’s assume that these paid things are $3.99 which is the average price of everything. If we pay for all the aircrafts, that is around $70 alone and if we pay for the regions, that is about $28. That is almost $100 that you will be spending to pay for everything that you have to buy to unlock. Now let’s add in 12 months of live which is $4.99 if you lay to choose the monthly option for 12 months for some reason. That is about $60 that you will need. That means that you will be spending $160 for the laid aircrafts, regions, and multiplayer. The yearly subscription is not even half the price as it is $50. So no, Infinite Flight isn’t costly to play and it is worth every single penny that you spend on this game.