I haven't looked at ecuplus in a long time. What's interesting is that it now has "ROM editing." Maybe I'm wrong, but that sounds like ecuflash...
The ECU+ [ROM Editing]
If that is so, then why spend $550? And then the Greddy is going to be about $525 plus $100 for the harness.
AWD_XTC, have you seen these;
EcuFlash - OpenECU
EvoScan OBDII Mitsubishi MUTII DataLogger Scantool
Mitsubishi OBDII DataLogger - EvoScan
... that's a lot of control for $110.