Cryptocurrencies always have something strange about their coin prices, including Ethereum coins which can be pumped at any time.
$100 in 2018 can definitely get more profits, even Ethereum in 2018 was around $300-$600, I'm sure that if Ethereum were bought now it would feel expensive.
For capital of $100 with the current price of Ethereum reaching $2400, there is very little profit to be made, but maybe with extra patience, one day ethereum can reach $20,000.