There are a bunch of server that has a huge imbalance or are very small and therefor barely playable. In the meantime some servers are just to big.
A way to fix this could be to have a dynamic transfer pricing.
It would then look something like this:
Transfer from high pop to low pop = free
Transfer from high pop to medium = 50% discount
Transfer to high pop from any server = full price
Same kind of pricing could then apply depending on faction imbalance on your current server vs the server you want to transfer to.
Example:
If your faction on current server is greater than 60% it is free to transfer to any server with a server where your faction is less than 40%
I believe this will give ppl an incentive to move to low/ medium pop servers to help out make them playable as well.