I am totally in favour of a seasonal server - I've been waiting for this for a long time.
However, like others I feel the pricing is a bit strange - you really run the risk of making this feel like double-charging. @Orlet has excellent suggestions there.
I understand why you would want to tie-in with the persistent game and help promote it, but I think you should seriously consider option 1 to just completely avoid the double-charging issue completely. If you do go for option 2 you are going to have to think very carefully about your marketing.
There is another issue I would like to raise here. I personally have an issue with subscription services and prefer to only buy lifetime subscriptions or not at all. Are you considering any kind of lifetime membership for the seasonal servers? Also, what about players who are only interested in the seasonal servers? It seems strange that you can't buy access to the high CPU seasonal server without also getting access to the persistent servers.
Personally I would choose to give up access to the persistent servers and only run on the seasonal servers, given the choice. Perhaps you've deliberately designed the pricing to prevent that. But it might be nice to have the choice. The lifetime subscription was quite an expense and I'm not really happy about possibly having to pay similar again for the seasonal access.
Another suggestion would be to have a fixed CPU limit on the seasonal server (say 100 CPU) and give players a choice of how to access it:
- Sacrifice 100 CPU on the persistent servers and allocate it to the seasonal server (with no other costs to access the seasonal server)
- Pay for one season of full CPU. No persistent subscription required. If the player also has a subscription on the persistent servers then it is unaffected.