I'm still debating whether to get the expansion pack day one or not. The problem is I have already so many other ways to play the Mega Drive games and the most exciting games that are available day one for N64 have been remade or remastered, so I would rather play those better versions. On the other hand, I never played some of the launch games like Sin & Punishment, Dr. Mario 64 and Star Fox 64. Guess I will make my decision after Ninty announced the upgrade fee.
Just in case you don't know- you can easily change the region of your Nintendo account (as long as you don't have any unused vouchers or funds), download the US app and change it back afterwards. The whole process doesn't take more than a few minutes and there is no additional account needed.