Lol, 20 milions or less is lowest option!?
OP probably dont know that most likly even Zelda BotW had budget of 20 milions or less.

No.... BOTW had a much larger budget than $20m

Here's what Miyamoto said in June 2016:

"Breath of the Wild has over 100 staff, and over 300 people in the credits, spending over 5 years. Our current efforts will be helpful in the next production. The costs will be recovered by selling in large volumes, passing 2 million sales."

If we assume that Nintendo only gets $40 profit after shipping/retailer fees that's still $80m to break even.

And the 2m sales to break even may have even increased over the next 9 months until the game released.

BOTW budget was probably between $75-90m

Basically however much it takes to make it great, it should be a big bag of cash, a blank check within reason to be a 90%+ rated game. Budget should never be mentioned if the game fails to meet players expectations basically imo.

It was Nintendo's most ambitious project so far. A big open world with a new 3D-engine and hundreds of developers involved for years... plus many non-developers (quality control, voice actors..). Their wages alone were probably already more than 30 million dollars.

Plus wage labor costs, costs for their computers, maintaining costs of the builings they used, etcetera...

I have no problems believing that the total costs without marketing were around $60M or even higher.

And it paid off. Not every Nintendo game needs that kind of budget, but I hope at least one prestige project per year gets $40M - $60M budget.

If you reason like that they should have kept the series dead to begin with.
Now they have the biggest chance to make the IP grow in popularity, it should get an adequate budget

Yeah you are right, but again, Zelda BotW is game that was 5 years in development and in one point there were more than 300 people working on Zelda game, and Zelda BotW had huge marekting push, I mean we even had hole E3 around Zelda BotW. I dont think that any other Nintendo game is coming even close with budget to Zelda BotW.

Honestly, Nintendo was willing to take a loss on Bayonetta 1 and 2 for Wii U simply because it gives them a better reputation with the hardcore going forward. I could see them wanting Metroid Prime 4 to be massive and critically amazing to attract more hardcore users to the system. As the years go on the sales may even justify the budget, but they definitely need a good budget to make this game worthy of being waited for as long as it has been after 3 and the 2.5d one.

Whatever is slightly above the average of a mid level franchise game.

Game doesn't need to be profitable in raw sales.

If it brings attention to a platform, meaning people buy said platform, which means those people buy more games... Then ultimately it doesn't matter if it is unprofitable.

Which I think is the issue Microsoft ultimately had with Lionhead/Fable.

With that in mind, I'll choose whatever budget that allows the developers to hit their design goals to release a solid product.

Is this a joke thread? Twenty million is an obscenely high amount for a Metroid game. Maybe 1.5 to 4 million at the absolute maximum.

Metroid is NOT a flagship IP, not even close. It’s bottom tier as far as Nintendo’s main IPs go. They outsource its development.