I think you should invest in ETH, and you can do so much thing with ETH: investing in ICO, holding, trading with margin,...
Generally speaking, if you invest your funds in the etherium, then you need to have a little more money for this. In any case, you can try to buy 1 etherium, and the remaining 150 dollars to buy other coins with small prices. As an example, you can bring worldwifi or XYO.