Even though bitcoin is not a stable coin that shouldn't discourage who wants to save up money to invest from investing in a wrong time, note, as the price isn't stable it makes it easier for any investor to save and invest whenever he wants to as no time is late to invest and to take profit. I think it is right to have have a stable income before investing in bitcoin since it will reduce the panic and fear of the investor but anyone who is investing with a little earning will only be hoping to get a quick profit which may never happen easily unless the price increased tremendously after investing so I think saving enough money and having a good and stable income should be considered by anyone before holding bitcoin.
There is no room to fear as you said all one need is to planned well and save before engaging on the investment, this can help investor to accumulate even more as the attention to quickly withdraw won't be there is a result of not planing properly that make most people that engage on BTC begin to consider withdraw so fast because they are choke with other responsibilities that that can't deal without venturing or touching tje investment,you can only see the value more when there some set outside strategy of handling some daily impressing needs outside one investment.
This is where the concept of emergency funds comes in. Remember that emergency fund was suggested as a way of protecting the investment from unplanned event that can lead to the investment being liquidated. With emergency fund in place, it becomes easy for the investor to relax and enjoy his peace when urgent needs arises. But care must be taken not to mistake the emergency funds for the funds needed for basic needs because are different and must be used as such. Emergency funds are set aside after basic needs have been met, it can be a fixed amount or variable and depends on the financial disposition of the investor.
I will advise anyone investing in bitcoin not to ignore this emergency funds. It has helped me a lot. Now I have peace of mind unlike before that I put all my money in bitcoin only to be selling when I have needs, this often made me sell lower than what I bought.