Mount Training

I was thinking about whether I should wait to get my level 40 mount for the prepatch, or if I should just get it now. I dont have much gold so Id prefer to save as much as possible.

I know the training is 20g atm, but Im not sure if that initial 20g training will be transfered to apprentice riding skill level when TBC comes out, or if you only get the apprentice riding skill if you own a 60% mount speed mount.

If the 20g training from vanilla gives apprentice riding, then I can save myself 15g, since apprentice riding skill in TBC is 35g.

As for mount costs, Im not sure how much mounts will cost in TBC.

Im very confused on how all of this works. I tried to research it but theres a lot of random info without a clear answer to it.