I don't think you're going to be able to get a 150w HPS ballast and bulb for under $75 anyway. Doesn't matter. A 150w HPS is around 13000-14000 lumens. You can do almost as well with CFLs.

I would go with this rig:

4 10.5" Clamp Light from Wal-Mart @ $10 each = $40

4 Y-splitter sockets at $2 = $8

3 3 packs, GE 26w (100 w equivalent) daylight bulbs (6500k) @ $7 each = $21

2 4 packs, Wal-Mart 23w warm white bulbs @ $7 = $15

TOTAL $84

It's a little over $75, but it gives you reflectors to improve light, daylight bulbs for veg, and warm whites for flower. That covers pretty much everything. 8 23w warm whites will put out around 12000 lumens...enough for a good 2.5 sq. ft. grow. That's plenty to veg 5 plants. If you're growing Top44, the plants will be small so you could probably get 3 plants through flower.