I'm at, um, 336 atm. Yeah, it's fun but it definately sates an investment of time or money!
Here's a couple of hints:
You can get skillups on grey recipes.
You can level lock on the Newb Isles, where rares harvest like candy.
Adept 3's transmute like Legendary - ie, more powders and a chance at an Infusion.
On the old Official Forums someoen posted they took a transmuter from 0 to max in three weeks entirely on T1 stuff, and didn't pay more than fuel costs!