Many folks end up figuring out how much they can invest on a regular basis (perhaps weekly?) and then just investing and building their bitcoin position over time, and it tends to take a decent amount of time to build up an investment so that later down the road the benefits of all that hard work, dedication and delayed gratification might have good chances of improving the guy's situation, even though such guarantee of improvement was not and is not present.
Some persons don't want to just start that has been a big problem but they are evenly ready to complain and feel bad when they see bitcoin price hit higher than it was when they were supposed to invest, trying to work out modalities on how to invest in bitcoin in whichever way that suits us individually has always been the backbone of many bitcoin investors, some bitcoiners has learnt how to initiate the habit of talkless and do more, it is not all about how much we have rather it is about figuring out our discretionary income on daily, weekly and monthly based whichver way we chose so that we can invest with it smartly and much more consistently.
I have realized that some people are not ready to make sacrifice for the future, they are always concerned about the present there by forgetting to work or lay foundation for the future, even when they have the finances to do so, bitcoin investment is a thing of the mind, even though are not sure of what's about to come in the future, history has given us hope that there will be light at the end of the tunnel.
Bruh, i think the biggest challenge most people face is not really about the money itself, but about mindset and discipline. It is easy to say i will start tomorrow or keep waiting for the so called perfect entry, but that delay later turns into regret when the price takes off.. The truth is, there is always going to be a reason to hesitate, but the people who actually build something out of Bitcoin are those who act even when they do not feel 100% sure...
Another thing is sacrifice like you mentioned. A lot of folks can afford that daily soda, those constant Netflix Subscription, or even weekly hangouts, but they never pause to think and redirect a fraction of that into stacking Bitcoin.. It does not take a huge capital to start, it just takes consistency and a little self control.. Over time those little pieces add up, but because people want quick results, they do not value the slow and steady approach..
At the end of the day, it is more about someone plan, vision and patience. If you think only about the now, you will always miss the bigger picture.. The early adopters were not sure either, but they planted their seeds regardless. That is why I see Bitcoin more as a test of conviction than just an investment.. You either believe enough to lay a foundation, or you keep watching from the while others reap the rewards later...