I completely understand that, I get that it takes a lot of work to make a track as detailed as the ones in GT5 are, but to charge us for tracks that were in GT4 and previous games is stupid.
Why? You're still not understanding the workload involved.
I'll break it down:
Art:
overall style, location, etc:
source images
weather effects (if applicable) source images/vids
Production:
high-res skyboxes
high-res textures (road, bricks, rock, sand, concrete, etc EVERYTHING YOU SEE)
high-detail models
baked normal maps
hires lightmaps
cubemaps/misc reflections/etc
vegetation
misc lighting effects
shadow optimization (what casts realtime shadows on what).
Track imperfections
Design:
Layout (rough)
Sand trap location
Barrier location
Pit area
Pit lane triggers (start/end)
Physics materials (lumping this in here)
Track imperfections,
locations
So for a track like, say El Capitan, as seen in GT4, one of the better looking tracks, nothing would be carried over. Every texture remade, with normal maps. Every lightmap discarded and new ones baked. Every bump in the road would have to be remade. Every white line smoothed again.
The pitlane would need a change, no way would it support 16 cars. How do you do that - make it longer, redesign the pit entry? Can't push the exit back. he sky has to be remade to something that looks good with the new bloom and weather effects.
The only thing that could be carried over would be an areal map, a topographical map, and reference pictures from Yosemite Valley. Anything in bold can be carried over. Everything else has to be new.
It's like you're saying the Transformers movies should be free to watch, because the franchise already existed. You're either ignoring of failing to comprehend they have cgi people involved with the project, and computer graphics takes a lot of time and money.