I can’t think of many things you can buy for a dollar, maybe a bottle of water and 2 pieces of bread.

Chewing gum maybe, back in the days those were cheap, doubt that’s still the case.

Photocopies, those are cheap, you can get like 7 copies with 1 dollar.

Can’t think of anything else, really.

Also earning more? That’s not possible, unless you’re willing to beg, but then that’s completely unrelated to your initial dollar.