As far as antenna on the cheap goes you might try a Loop Antenna. They really are usless for ham as the cheap ones are not really any good but could work for your use case.
There are many more. I wouldn'y use them with any power but at HackRF levels you should be safe.
No one antenna is going to be optimal for all things. That being said for international (shortwave) listening this is one of the best things you can get:
https://www.amazon.com/MLA-30-Antenna-Active-Receiving-100kHz/dp/B085ZSXF8Z