What you said was they most definitly went and started developing GT5 right after GT4 because they aint got nothing else but GT5 to work on......ohh well misunderstood you I guess.

thats how a lot of ppl  refer to GT5P....a demo.

Which will say something for the end product, won't it?

sure?..........

*scratch head*

It will probably make a profit within the first week of being on sale, if you count in GT5P profits.

GT5p had a lot off content.

71 cars, 6 tracks, online.

Cant call it demo if comparing to other games,

but if u compare it to GT5's (1000 cars, 70 variations of tracks in 20 locations, NASCAR, damage, go-carts and only Yamauchi knows what else) it does look like demo.

it has easily been covered

They developed Tourist Trophy after GT4. Polyphony Digital didn't start development on GT5 until late 2006. 

PD would get about $15 for every GT5:P sold. 5,000,000 x $15 = $75,000,000. They are already in profit for GT5 before its even released. Every copy of GT5 sold is pure profit for PD.

Prologue should have already resulted in a profit unless they are lying about the $60 Million figure

They probably did not make a profit for all of GT5's costs. But Prologue probably financed the first 3 years or so of dev. with all the money earned.