Steam are having their annual Holiday Sale, and one of the games that were on sale on day 1 was the newly released FSX Steam Edition. So if you haven't gotten around to trying FSX yet, I doubt you're going to find it much cheaper.
FSX Steam Edition is basically FSX + Acceleration, updated with some added Windows 8.1 support. There may be some minor issues with some commercial 3rd party stuff (FSUIPC is one, I've been told), but other than that, everything that was made for the original FSX version should still work fine.
It can be purchased here: http://store.steampowered.com/app/314160/
Do note that it requires the Steam utility to run in the background.
The download hangar is currently disabled. We're doing our best to bring it back as soon as possible.