Depends on your class I guess, and probably how expensive the potions are. Only got around 400hp on Wizard by lvl10 so 12500 seems a complete pipe dream for him but I suppose a tank type frontliner with lots of vitality might get well beyond that.
The wizards Arcane Power is funny. He gets 100 of it and it doesn't increase with level... and I got an item that increased it by 1 ><
Tried out the witch doctor second for a bit. Really enjoyed it so far, but I wanna try out the other classes before the beta is over so won't get chance to try out much more on her. The Grasp of the Dead spell is awesome. Firebats was far too expensive for my liking.