Actually, you should buy what you really need, but if you don't need it, then don't buy it. A few days ago I bought a phone. I really needed the phone, so I sold my saved Bitcoin and bought a mobile phone, but it wasn't very expensive, only $215, I couldn't move forward without the phone. I had to stop all my work, and so I was forced to sell Bitcoin to meet my needs. That's why I want to say that when you really need something, you should buy it, but I won't say anything without reason because investing in Bitcoin without buying anything unnecessary will definitely be profitable.
That is not a very good investment structure and this is not something anyone should normalized. This problem was not that you actually needed a phone, the problem is that your Bitcoin was your back up plan. And this act just prove that there was no proper financial setup in place. See in Bitcoin, when your mindset is in long term, you are not supposed to dip in just for basic needs or predictable needs.
I can't even say that a phone is an unexpected emergency, It is a predictable expense, so when something of that sort actually forced you to sell your Bitcoin, that is a evident that there were no backup funds, no planning and no separation between investment and daily life expenditures. That is not investing, that is simply poor allocation.
This is precisely the way how people interrupt their accumulation and end up later complaining that they did not get to enjoy the benefits of holding, the problem here is not the market but the structure.
The best Bitcoin approach is very simple as ABC, which is to invest only what you can actually afford to leave untouched. Let me tell you, if you are still in a situation where you are actually forced to sell your Bitcoin, then even increasing your Bitcoin should not even be on the list, but rather the focus should be to fix your financial structure, to create backup funds and understand your discretionary income.