Two Wal-Mart 10.5? Clamp Lights--$10 each
Two Wal-Mart Y-socket adaptors (so you can put two bulbs in one socket)--$1.50 each
Two GE 26w 6500k CFL bulb 2-packs--$7 each
One four pack Wal-Mart Warm White 23w bulbs--$7

Total--$44

That's the minimum, IMO. That covers both vegging (6500k) and flowering (Warm White = 2700k) bulbs. You can veg 3-4 plants to get one female, and have enough warn white lumens to cover about 1.3 sq. ft. of flowering plants...enough for one decent plant. You've got reflectors to help avoid lost lumens. You've got clamps to place the lights...if you need chains and S-hooks, add another $5-$7.

You won't be swimming in bud or anything, but you can grow a plant with that amount of light. Make sure you have a space white good reflective walls...buying a couple of cheap mylar blankets at Wal-Mart could help. Keep in mind that we are talking about one decently sized plant...you won't have enough light for two. For most people, HID lights become a better, cheaper option pretty fast.