Go to Wal-Mart and buy light sockets with 10 1/2" reflectors for $10 each.
For each of the reflectors, get 2700k (warm white) bulbs and 6500k (daylight) CFL bulbs. Get at least 23w bulbs (they'll list them as ("100w equivalent" or something like that). You can get a four pack of Wal-Mart's house brand 23w warm white bulbs for $8. A two pack of GE 27w daylight bulbs is around $7.

So--four reflectors = $40
Two four packs of 23w CFL bulbs = $16 (Use these for veg.)
Four two packs of 27w CFL bulbs = $28 (Use these for flower.)

Total $84. CFLs won't have many cooling issues either.

That's around 13,000 lumens of light...enough for about 2.5 square feet. You can grow two decent sized plants with that, no problem.