Caiman lizard is way too big/expensive, chameleons will run higher than your budget and also not do well in an enclosure that isn’t a screen enclosure (more than one should also not be kept together because they will stress and fight). Leachies will run at least $800 most of the time, the lowest I have seen one is $500 and they also need more vertical space. Day geckos could work but you can’t handle them because they tear their skin off. Leaf tailed geckos are expensive and usually wild caught (giant leaf tailed gecko is even more expensive and rare). Sand boa doesn’t need a huge enclosure like that especially as a baby. BTS needs more room to turn since they can reach 2ft from head to tail in some cases. You could do a group of emerald swifts but it would be difficult to manage humidity since they live in cloud forests in the wild. Most are wild caught but captive bred pop up towards the end of the year. Crested geckos are also quite small for an enclosure that large and may have trouble finding food/water and a baby would probably have issues surviving in it, and vertical space is better than horizontal just like with leachies. A single nice dart frog can cost around $100 and an enclosure like that would be hard to set up for multiple given the equipment (misting system is strongly recommend+a bioactive setup) and they are small so it will be hard to make sure they get food. You could get a pixie frog if you wanted, but basically all amphibians are a look and don’t touch creature because the bacteria from our hands can go through their skin. A green keeled lizard needs good humidity as well, but the size of tank would work with it. All parrot snakes I have seen are wild caught and cost at least $200-250. No clue what their care is but you have to factor in vet bills since they likely have parasites, and even after that they can die on you from stress (that is a risk taken with any wild caught animal).