DX'ing is a radio term for looking for radio signals from far away. AM broadcast DX'ing is the hobby of trying to "catch" as many far away AM radio stations as you can. AM broadcast signals by nature can carry for hundreds, if not thousands of miles at night. Radio hobbyist have been DX'ing since radio was first invented over 100 years ago. Many DX'ers keep journals of all the stations they have heard.
This is probably the most rewarding low dollar radio related hobby there is. The stuff you need to get started is probably already in your home. Even if you have none of the items required, you can pick up everything you need to get started for under $10 at the local thrift store. How's that for low buck hobby?
You might be saying...
"I can listen to whatever I want on the internet."
Yes you can. Listening to far away stations via radio though requires skill, some understanding of radio waves, luck, and no dependency on a middle man (the internet). It's just you and the broadcaster with nothing but air between the two of you.