Have you ever experienced a laggy server host no matter how much you spend on upping the RAM then the CPU is likely to be the culprit. Especially for games like Minecraft which are heavily reliant on a single core for much of the servers operations, in this case having a core that is able to boost to higher frequencies will prove to be a large improvement.

In short choosing a premium host will give your player base and friends more time to enjoy the game and less time complaining that the server can't keep up with your adventures,