if you wann go cheapo go to a thrifts store and buy a florescent light.

any kind will work
shop lights,
or those circular bulbs used as a reading light. (the kind with a magnifying glass are cool for begginers!
you can adjust the light to the plant and really watch it grow.

or you could spend a few bucks and go with COMPACT FLORECENTS!

but you'll soon want a HID light. good luck