If it reaches $100, why would that make it not easily spendable? I bought bitcoin at 2000 USD and I bought some at 11 000 USD, because I believe in it and I believe that more people will come later and buy so the price will go higher and higher. So it doesn't make sense to say that people will stop buying if the price will be 100 USD.
Just look at Litecoin. I remember not too long ago when the price was 60 USD, ok that is under 100 but now it is 300 USD and people keep buying.
Indeed, a higher price doesn't mean that MONA won't be used as mean of payment. You can send fractions of it and it's much cheaper / faster than BTC for remittances.
MONA can really benefit from a rising awareness of Japanese people on crypto and from those who think they missed their chance with BTC.
It has a great tech. You can buy stuff online with it and you can buy MONA against fiat at Japanese exchanges. This is a huge plus for an alt.
Finally, I like the fact that cryptos are now legal in Japan.
In case some major country passes a tough law against cryptos, investors should regard Japan and its number one Altcoin MONA as a safe heaven.