I think you are underestimating it. The thing is that Ethereum has done a lot of Lisk's work for it already, with the past year going from 0 to $10.
I don't think Lisk will have to go through those growing pains. Investors will already see potential for $10 Lisk and bring it to $2-$3, and whatever happens after is up to the devs.
I think it is reasonable, Ripple was how many billion. Lisk is going to be an instant market cap, like Pepsi, vs Coke. Coke came out of nowhere and built up a brand from scratch, then Pepsi said me too, and boom, instant market cap.