This amount was impossible for me not long ago. But try make some calculations with x4 less.

25$ a week (instead of 100$) is all that you need to keep yourself started. It equals to roughly 100$ month or 3,28$ daily. I don't know in your country, but in mine that equals to a few drinks in a weekend (~8€ each) or a decent menu in a 'middle' restaurant ~15-20€.

Everyone has that and slowly (but also fast that you don't notice) adds up.

Everything matters. Everyone can 'moderate' a bit and cut a few unneeded expenses and purchase some BTC.

For example, my old (and a bit outdated) Iphone 6 from 3 years ago should need an upgrade. I purchased that phone for ~350$ back in late 2017. I would change it but I'm happy with it and more importantly. IT WORKS FINE!

In that same timeframe, I have friends that bought 2-3 500-1000$ phones. They still have less than 1000$ in their bank account and live payday to payday.

Most can't delay gratification. Learn this and you're all set.