If, and that's a big if, there were any free transfers, it would be away from the overpopulated servers, not toward. They are locked for a reason and a free transfer to them would completely defeat the purpose of locking them in the first place. If you both absolutely must play on an overpopulated server, pay the transfer fee. Personally I think it's silly to be able to transfer to locked servers at all, but it probably makes SE a pretty penny.