....if I want to play the older PC games like "Operation Flashpoint: Game Of The Year" up to Microsoft's "Flight Simulator: X"? I'm wanting to set up my own home cockpit, it you will, and I'd like to know how expensive it would be to set it up to use the system that would play the PC games that I've mentioned?

I'm a huge Airwolf fan and I know that the helicopter can be found in both games. I'm getting weary of playing "Grand Theft Auto 4" just to acquire "Airwolf" in the game. And, I don't think I'll ever be able to afford the Vario r/c version 800-size "Airwolf".....

Any help?

Just consider that for older games like OFP you needn't buy the whole modern setup. Probably OFP doesn't even support the latest gen gaming gear.
In other words, strictly speaking your undertaking isn't expensive. However, it might become expensive if you find yourself on ebay shopping for decade old stuff.

Thanks, friend. I'll take those things into consideration. I know that OFP: GOTY edition only apparently runs on systems using Windows '98....that's why I was wondering what I would need to run both OFP and Microsoft Flight Simulator X (which is, of course, newer) on the same computer?

Oh don't you worry too much about your OS. OFP runs on Windows 7 without further ado, but I doubt anyone's tested it on Windows 8.X or Windows 10 yet.
What I meant was you should keep an eye out for controllers, joysticks etc. that went on sale before Windows Vista did (as that's when Microsoft introduced a new port technology that might not be fully supported). Could be wrong, though. Never used any of those. The latest update's change log might answer some of your questions, that would be from late 2005 I think.

I've already decided that I want to purchase the Saitek Pro X-55 HOTAS joystick/throttle because of it giving me a better "feel" of what it would be if really flying "Airwolf" as in the telelvision series since the controls are separate.

(Told ya I was a huge Airwolf snob!) Thanks for the info!! It's very much appreciated!