it should only be $20 per year.
Sony and Microsoft offer a large range of content with online functions. Nintendo is opening with MK8 Deluxe and Splatoon.
Sony and Microsoft grant their subscribers 4 free games every month and they are allowed to use them as long as they pay for a subscription. In Microsoft's case, Xbox 360 users dont even have to keep paying in order to keep the game. Nintendo is only offering 1 classic game per month, and it disappears once the month is over, regardless is you keep paying or not.
Sony and Microsoft have multiple apps that use voice chat while playing games online. Nintendo might not even have any form of voice chat built into the Switch and rely on smart devices.
the Wii U and 3DS also still have free online functions making the Switch's paid service less enticing.
If they really think they can charge a full $60 annual paid service, they will be hit with huge backlash. as for me personally, I will not pay anything over $20 annually