chams
Chameleons are an animal you don't want to take shortcuts with. Some enclosures do have 3 sides that are screen and 2 sides that are glass, but i would recommend getting or making an all screen enclosure (other than the framing and the floor of the enclosure).
It would be in my opinion, a good idea to save money, do alot of research on these animals, and then when you have everything you need for them make your purchase. Before I bought my chameleons I made sure that I knew the basics front and back, facts like Humidity, Heat, not housing these animals together, furnishings, enclosures, use papertowel or news paper instead of substrate, foods, calcium regiment, knowing the importance of proper UV lighting, and just husbandry in general.
It's alot of stuff to know, but when everything is done properly chameleons are an exciting and rewarding animal to invite into your home. Do your homework, stick to a plan, and you will have great success with chameleons!