i think that the drifting / sliding characteristics of canyon are great !!! a

Agree, of course you need more training as in other environments, but you really can use these blocks to create wonderful tracks, and hunting is here even much more fun than in other environments

Exploding Lemon»LT says:
each environment is $25 each, which means that if everything goes the way nadeo wants it to go. to get every environment in the 3 games would end up costing $225-$375+

So there will be like... more than 10 expansions/different environments for Trackmania²?!

I think he was including the environments of SM and QM.

Planned:
Trackmania² - 3 Titles (Environments). Canyon and Valley are first and second of these Titles.
ShootMania - 3 Titles (Environments). Storm is the first. Cryo is probably the second.
QuestMania - 3 Titles (Environments). Names unknown at this stage.

ShootMania is a First Person Shooter. QuestMania is an RPG. Both are launched from within ManiaPlanet and will share the same ecosystem. How much interaction between these Titles there will be remains to be seen. We do know that each game shares the easy editor that we've come to love in TrackMania. And they will probably share a similar feel of gameplay. Easy to pick up, hard to master.

At one point, back in 2010, Nadeo said they could make as many as 15 environments. It was their "ambition". However, for now they've only planned to make 9 total across these three genres.

Yes, if every Title costs as much as Canyon, we'll end up paying quite a bit over the next few years. I look at it this way though. I get so much replay value out of TM... it saves me a ton of money on other games. I'd rather give Nadeo that money I saved if it enables them to continue to develop the only game I truly love to play.