I do not think that the price will grow very quickly ! I think that it will grow smoothly and in any case it will overcome the mark of $15,000
It is difficult for a coin to grow smoothly because the market always has a certain cycle. If the ETH price does not increase rapidly, it won't reach $15,000 in next 10 years.
For that, if ETH will launch Etherium 2.0 with improved scalability by sharding and Plasma, limited max supply and masternodes - $15К price will come true.