It is so much because so much development went into it. And it also comes with a well made controller. If you're on a budget, picking up an older version of Real Flight or one of the others is a good bet. I see Real Flight 3 for sale sometimes between $50-$75, and it is upgradeable to the newest version if you decide you want it later. I used FMS when I was starting out and it is good enough to help with orientation and basic control, but it doesn't simulate any stall effects, ground handing issues, or wind.