@xp29
Absolutely agree! The right conditions from the beginning on are essential.
Okay! I have definitely considered that, but as I have done my research and talked to many people, starting the babies off in a smaller cage will allow them to grow bigger in the long run, this is because they won’t waste as much energy running around their cage and chasing insects!
This is for sure not the case:
1. Why does a beardie need to get as large as possible? Might look impressive for us humans, but otherwise, not necessary. Of course a beardie should not be stunted in grow (as it could be from wrong light, wrong food - we see such dragons in the forum sometimes, especially rescues), but otherwise, as large as possible is not better. In general: Larger animals of the same species often have more health issues and don't live as long as slightly smaller ones do (unless, of course, the smaller size is a result of wrong conditions).
2. Most insects, usually, don't need to be chased. And even if (not bad if a dragon can do that!), a dragon who is a pet living in an enclosure will move ways less than a dragon would need to do so in the wild. Movement builds muscles - more muscles stabilize the joints, more muscles allow for more security in their movements. Movement is also improving bone growth. So exercise is not "wasting energy"

3. A large enclosure allows a dragon to use different temperature and light zones (the temperature gradient), to explore, to hide, and also to hide and at the same time observe (especially beneficial for a young dragon that still feels insecure). A larger enclosure also allows them to avoid walking through poop. My dragon just poops at a specific place in his enclosure, and then avoids that area - which he more likely could not do in a smaller enclosure. (Some dragons might even walk through poop in a large one with ample space, but the size of the enclosure just reduces the change. My dragon never ever walked though his poop, and also a benefit for me: I never had to wash/
bathe my dragon. Benefit for my dragon: less contact with poop reduces chances of infection, and a healthy dragon who doesn't have diarrhea or loss of appetite will grow better, thus having better chances reaching a reasonable size.)
So don't worry regarding getting a large enclosure right away

Your enclosure might not be too small right now, but a larger one also doesn't "hurt".
(My beardie is in a 200 gallon enclosure from the beginning on. He's now 13 month old, weight is 500 g, length I would have to check. If I would get another beardie, I would do so again for sure.
There are also other people in the forum who have a large enclosure from the beginning on and have not observed them not reaching a normal size.)