The price tag for Nintendo probably is too steep for Disney, Nintendo's cash holdings and equivalents (that could be turned into cash within a year) are almost $12 billion ... meaning the entire company would probably require at least $18 billion to purchase when factoring in the value of their IP and the fact that you generally have to overpay a bit to get a deal like this done. Probably closer to $20 billion actually.
Buying Marvel + Lucasfilm combined only cost Disney about $8 billion.
To be honest in hindsight, Nintendo maybe should've bought out Marvel years ago, that would've been a great investment I think.