I voted "Too much", but now regret it after reading more about the expansion, and thinking about it all some more. Honestly, while I would have liked to see a lower price, I think the asking price is not that bad. I am certainly willing to pay it when the time comes, and given how many hours I get out of Civilization games compared to almost everything else, it will end up being very good value for money.
I also just appreciate the business model more: fewer, larger expansions rather than bits and pieces of content which end up costing more, while doing less for the overall experience.
It seems Gathering Storm will have a lot of new stuff, and I think it will be worth the price.