Why don't you just repair the connector? It's a regular 3.5 mm mono plug, RadioShack sells a pair for $3.

If your RealFlight is Classic, Deluxe, or non-Interlink G2 (i.e., sold with either parallel port interface or game port controller), you can use many 3rd-party interfaces, e.g. from www.milehighwings.com. If your RealFlight is G2-Interlink version (the only G2 version currently sold by Great Planes), then it will only work with its Interlink controller, which also serves as a copy protection device.

Hope this helps,
Boris
[8D]