It's a bit hard giving general advice without knowing more about you. From what I understand here is that you have a good salary from which you can save money each month. Having a fixed savings rate that we take out from our salary immediately is the best approach to not overspend and will lead to longterm financial stability. A few years ago the question between fiat or crypto currencies was easy to answer because the interest rates where so low and there was no point in saving fiat money. But the world looks a bit different, banks are offering up to 5% for a savings account with new money. This increases the opportunity cost for cryptos and we need to make sure we can achieve those returns. Bitcoins is definitely a great longterm investment to save money in, but when choosing alt coins to trade we need to make at least 10% per year to compensate for the risk we take.