Swopping barns is not only a big deal for you but also your horse.
Sit down with a sheet of paper - "what's wrong with the existing barn and
What is right with the setup?"
Then try to do the same paper exercise with the new barn."
Routine is important for the horse but many horses adapt quite well to change with time - in the olden days horses were locked up (sometimes in stalls) whenever they were not working but there again they worked a lot more than horses do these days.
The one thing I value about my barn (in English read "stable yard") is the wealth of expertise in the other owners that there is to call upon whenever a problem presents itself. With a 3 yo horse, you need help in bringing both yourself and the horse on. The downside is that when another horse in the barn gets a cough - then quite often the cough goes round.
A very important thing to do is to talk with the other owners - get the gossip - disregard half of what is said and then ask yourself if the place still sounds Ok.
Money - well you own a horse don't you. It is never going to be a cheap hobby. If you have a horse, then you'll always be short of cash. The question is "can you afford it?"
PS You can always go back if it doesn't work out.