If you have $150 betetr you buy or invest your money at litecoin, how ever buy or invest at bitcoin is not good solution with your money too small, you can invest at litecoin because price still lower and you have much profit later when price is up.
How does the amount of investment affect which coin you are going to invest in? With this logic, it is best to buy a scam coin that costs 1 satoshi and wait for a miracle. I would recommend buying Bitcoin, especially if you are a beginner and you cant distinguish a truly worthwhile project from a fraudulent project which is a lot on the market.