The price for a massive adoption, where it would be a success (in the way you put it), would be at least 100k.
We have a 10K Bitcoin (OK, 8K) because people speculate on future adoption. It isn't the "fair price" for a currency used only by some 20-50 million people.
The 20K Bitcoin of mid-December had a "market cap" of 320 billion USD. This is not a low figure: it's half the value of a company like Facebook or Apple whose products are used by billions (and all cryptocurrencies together had a market cap above that number).
The US dollar has a M1 supply of about 3,5 trillion. This was only 10 times Bitcoin's market cap at its ATH. The US dollar is, by far, the world's most used currency and has probably millions of transactions per second, while Bitcoin has 5-7 (at most, at this moment we only have about ~2 tps).
Bitcoin's price would be much lower if there was no speculation on future usage. I consider speculation on future usage a completely legitimate strategy, because Bitcoin has an enormous potential. But it's false that it wouldn't work as a niche currency at $100 a coin.