Now what you're going to need is what's called a "job". Now what a job is, is "a paid position of regular employment." Soon enough you'll be seeing green come your way.

Now do what you can do is create an account with whatever bank's in your area

Get your card information

Put that information into your Steam account

Go into the shop

Hit your "R" key to "buy credits"

Select the 10,000 option as many times as you'd like

And there you go, enjoy. :^)