CFL's get the job done. I'm using 4 23 watt bulbs. one full spectrum, one 4500K and two 6500K the more the merrier.

the pic attached ran about $38.00
including hardware,bulbs and ceiling mount pulleys for height adjustment. it's growing green healthy plants however I am upgrading to 48Watt bulbs soon simply for faster results.

you can look all over you-tube and see successful CFL lit gardens.

I want to begin with hydroponic gardening, but i don't want to spend too much money

hmmm, those are indeed conflicting desires! It seems like everything hydro is expensive.

Provided that you supply enough lumens for your space, CFLs will work fine for lettuce, greens, herbs, or anything leafy. My advice is to stick with those crops if you use CFLs. Fruiting and flowering crops do far better under hid HPS lights, which are expensive to buy, to power, and to cool.

grow outside or in a south facing window if you're anywhere in the southern US and you don't need artificial lights.

Lighting fixtures are expensive.
Electricity to run lighting fixtures is even more expensive.

You can easily make hydroponic gardening efficient and economical.

Look at each aspect and try and use "non-specialty" products when available....for example....a hydro store may charge $6-10 for a black 5 gallon bucket while home depot or lowes will charge $3.oo

There are also "grow lamps" for 60-70% more than their identical generic bulbs......look for 6500K for growth and skip the "grow lamp" temptation.

There are so many ways to save and make it economical.

Try a do it yourself Deep Water Culture System.

Here is a link that might be useful: DIY Deep Water Culture System