There is currently no minimum limit on the amount of money that falls under the category of investment. You can invest whatever amount of money you have, even starting from US $1. In my country, the government has even initiated a campaign to encourage the public to start learning about investments. Stocks are sold through an app that is monitored by official regulatory bodies of the country, and they can be purchased starting from IDR 5000 or approximately US $0.33.
The goal is to let everyone know that investment doesn't always have to involve large sums of money. Saving little by little for investment is also a viable option. The accumulation resulting from the discipline one exercises will bear fruit when the future arrives.
This means that someone can work, sell their services, and use their earnings for investment, leveraging their exceptional thinking abilities. The amount doesn't matter; it is the thinking capability that makes it better.
This is really only practical if your expenses are much less than a percentage of the expected future value of the investment. If your investment profits keep getting wiped out by monthly and sudden expenses, then investing is not going to work for you. That's why it's impractical to invest like $10, possibly even $100 as the profit will be generated to slowly.
P.S. If knowledge is waste without money, then what is money without knowledge? A toy in fools hand? Necessity?
Judging by all the ridiculous shopping sprees and bad money management making the rounds, I'm pretty sure it's the former.