You may have heard of the 50/30/20 strategy (for managing money), where 50% goes to essential expenses, 30% to spontaneous purchases, and 20% should be saved each month. Well, I've been putting that 20% into crypto for several months now, and I find it to be a pretty good decision. Some people just save money at home, others put it in the bank, but I invest mine in crypto coins. That’s how I started acquiring my first BTC.By the way, the 50/30/20 strategy is actually pretty good 
This is actually the first time I have seen someone put the 50/30/20 strategic budget/planning into play, and you are actually doing something good with your 20% by investing it in crypto, but if I were in your shoes, I couldn't invest more than 15% and leave 5% as fiat savings in case anything comes up that is not included in the 50/30 budget; I can easily put my hand in the 5% reserve fiat and save myself the stress of selling part of my acquired crypto unripe.