Might be ok, depends what he comes with.
A 2x2x4 cage goes for ~$90-110 depending on where you buy from. A full grown veiled should be worth more than a baby, I would say you could buy an adult for around $100. UV Lights are $20, plus the fixtures and such. So the price seems reasonable if you're getting the cage and accessories.
HOWEVER, word of caution, I would request to see the chameleon in person before you buy him. Any photos they have can be deceptive and/or old and you might not be able to tell if you can see any health concerns like being underweight or showing signs of MBD. Definitely don't pay until you've had a chance to check the animal over! I've heard about people being tricked too many times.