The demand for simulators and R/C products in general is there, and in mass quantaties. How many times have you had your plane (1st break in tank, no flying or taxiing), helicopter (1st break in tank, or electric "park" heli), or car outside running in the neighborhood and someone comes up and starts to ask about it? They think it's really cool, but get turned off as soon as they ask the big question, "How much does it cost?". When you say something in the neighborhood of $500, they get shocked, and the RC hobby has lost another customer. People have the Wal-Mart price mentality and think that all RC's should be under $100. Granted, we know that our Blade CX2/Axe EZ/insert coax heli here is better than the Air Hog helis sold for $60. The general public that has never had exposure to hobby RCs are looking to buy things cheap.
If a company like Horizon would take a heli like the mCX w/Tx for $129.99, include FSOne Solo w/ an interface to connect it to the included controller as well has a Horizon catalog, advertise it on TV and/or other mass means (in a target "test bed" area first), and sell it at Wal-Mart, Target, or Radio Shack, I think that they would do well. As a test bed, only sell it at a couple of stores to see how many people actually respond to it. Once they buy that heli, enjoy it, see how much better it really is, look through the included catalog, then they would be more prone to look for an LHS or the Horizon website to buy the larger, more capable, and more expensive products.
Similar could be done with FSOne since they've lowered the price, even if it is temporary or clearance. Even at $100, it would be possible to get people to buy it at Best Buy, Wal-Mart, etc... Just look at the game Guitar Hero ($90-$100 depending on console, $50 for Nintendo DS), and Rock Band ($160+). As for Microsoft's flight simulator series, $60 for the software, plus you have to buy your own controller to get any enjoyment out of it ($20+ for a decent joystick with rudder capabilities). By that time, you've spent at least $80 to get flying on that. They can also invest a couple grand into a demo Kiosk at the testbed store to let people try it before they buy it to get more interest in it.
The later would probably be the best bet, as high end companies that begin to mass market their product usually get labeled as a mass market company and don't get the as many customers looking for a high end product. Take Mongoose bikes for example. Years ago, Mongoose bikes were considered top of the line. They ran into money troubles and decided to add a mass market line under the Mongoose name (the bikes sold at Wal-Mart). Once they did that, many people looking for a high end bike would see a Mongoose at a bike shop (still the high end Mongoose of before), and pass it up thinking of the bike they saw at Wal-Mart earlier. Now, it's hard to find a high end Mongoose in a bike shop. Some bike shops still carry them, others can order them if you ask for one, or you can order them on the internet.
If they mass marketed just the sim, they would not loose their high end image by mass marketing their planes, helis, boats, and cars. They would be using the mass marketed sim to advertise their "real" RC products. That would open up the sim to a larger market, making them cheaper for us in the hobby, allowing the developers to make more money off of the product, and possibly get a few new people into the hobby. As a plus to Horizon, those new hobbiests would most likely look for Horizon branded products as a result.
The same could be done with RealFlight for Great Planes if they were willing to drop their price to $100 or less.
I'm not a businessman or a marketing specialist by any means, these are just my opinions and observations.
Maybe Mike is keeping an eye on this thread.