It's already OVERvalued because it's a digital currency, yadayada. It's already 4000x ish over the market price of when it first started.
I think bitcoin still not over valued even its just a digital currency because of demand and supply the price should be high.. and i think it will increase more in the following year. because we are developing and users are increasing.. thats why bitcoin will bbe more high value.. and i think someday bitcoin will be instinct and the more less supply the higher the value..