Megasquirt only costs $120? I know if you look around for a little bit you can get an AEM Used with all the sensors and so forth for around $1200 and thats for a DSM PnP. From what I have seen it's even cheaper for other more popular applications.
I do get the point you are getting at fordified. For some reason the megasquirt just doesnt compare when it comes to tuning abilities to me.
For those looking into the megasquirt...
http://www.bgsoflex.com/megasquirt.html
My train of thought is when I have so much money spent on a nice fast setup, why go on the cheap end when it comes to controling the whole thing. To me using a megasquirt on a race car is like putting snow tires on a 9second race car.