"pay for two": Are you sure? When I played Eve (a long time ago) you could have three characters training skills (only one actually playing) on a single subscription.
After that it was possible for a long time to have your character training a skill while you subscription had run out. That was a good way to make a specialized alt with Battleship 5, etc. for half or 1/3 the cost of a full-time account.
However, they fixed that as well a couple of years ago. They did add a skill queue though!