Even if you have higher income its always good to put only certain percentage of your income in bitcoins as you never know what will happen to bitcoin in future and if price falls then it will give you big loss.
It all depends on your tolerance to risk. If you have higher tolerance to risk, then go ahead, invest a larger amount in bitcoin. Just be sure to invest only the amount that you can afford. It is true that you can lose big if the price falls but you can also win big if the price goes up. What matters here is that you know the risk you are taking and that you will not go insane if you lose that large sum of money.