In my opinion this is your good plan if you want invest in eth. I want give you a suggest, don't invest larger amount because if btc price will not countinue then eth price come back down again. The capital bag very important now in our life so you should invest two more currency if you would invest larger capitals.
The current price of ethereum is increasing so Op should decide because the price is really improving in the market. That's right do not invest a large amount if you are just starting. Just invest the amount that he is willing to risks since we all know here the price is volatile.