Yes, it is expensive, but I recommended it over FS because the flight dinamics and the "sense" of flying. There are now a lot of airports and plane models mostly free, that let you do not expend more money if you don't want.
Do not miss the point that under Linux it works fluid and like a thunder (most of the time I reach 30 or 40 fps). The problem is to make all the plugins and things needed for on-line flying put to work. I expend nearly two months each time I change from distribution to reach this stage. :'(
Now I have the system working and doing well. My system is a 2600 Mhz Quad-Core, 8 Gb RAM with a NVIDIA Gt-560 Ti running on Debian "Wheezy" 64-bits (the better distribution for stability and flavor I ever found for home, work, play and fly on-line).
Linux Mint is not bad, but a bit short. I ditched Ubuntu 12.xx (since 9.xx) because the Gnome 3 thing, problems with python, pulseaudio and a hell of problems only because they want to be the most improved linux. That gave me a lot of problems each software update.
So now I have the system running properly with sound, Teamspeak, XACARS, FS-Economy (X-Economy) and a lot of plugins (32 bits mostly).
I you want to go for it, drop me a line and I will help you to put the system at work.
Bye