As i said on the sng threads, i've played in the sng's on stars, and i play the 3.25$ 6-handed's, 150$ bank should be well plenty to start getting into them, really, the players are so terrible that it's hard to NOT make money there.
Also i'd say maybe play a few HU tournies to get your HU skills honed for when you do make the final 2, the experience will help alot when you get good at SNG's an consistently make it to the final 2, as there is usually a big diff betweern 1/2 prizes.