They are slightly expensive to care for - $60 for her UVB/UVA bulb every six months (I personally use two UVB/UVA bulbs for her so that would be $120), $20+ a month for her food, and $20+ every two or so months for supplements.
The space, attention, and time they require is a whole other story, i would say it is beyond any other reptile you can own but in the end it is very rewarding.