The Grapes of Wrath
"No more use for anything." This man is selling his car for $1oo. Obviously, most people couldn't afford luxury during the Great Depression and cars were a luxury. Selling you car was a no brainer if it was hard to come by food and necessities for you, even if you only got $100. That went a long ways in those days, and if you died of starvation, that car was obviously no more use for anything.
This is one of the very rare, very disturbing images of a woman that is having to sell her 4 kids. She obviously knew that if she wasn't able to support them anymore, and if she couldn't find a place for them, they could die. This is just something that is heartbreaking and the mother is clearly ashamed to do as she's hiding her face.
"Well, take it—all junk—and give me five dollars." This is a place that one would go to get any bit of money they possibly could. They may not give you much money, but it is sure better than having something useless with you or just getting rid of it. These were important places during the Depression.
These were fairly common sights in the Midwest and places during the Depression. Farmers really got hit hard, especially with the Dust Bowl, so many had to sell their farms and land, even if that is the place they had always lived and been, which was often the case.
5 cents may not sound like much, but for these people it was. Yes, they are selling food, but you can't live on apples alone. This would be common for poor people to both buy and sell apples for 5 cents during this time.