Hate to sound crude but a major consideration is money. Make sure you know how expensive chameleon keeping can be AFTER the initial outlay for your baby and it's stuff.
Be aware at some point you likely WILL need at least one trip to a reptile vet. If you don't think you can afford that (you'd be surprised how often I read that)
There is often an emergency (or at the very least, drama) waiting in the wings.
Don't mean to put you off, but it's always good to have both eyes open.
That being said ... welcome. Hope you join the addiction!