Cheap macro ring lights can be usable, but they usually trade away performance and features.

Based on the community answers, the main differences are typically:

• lower build quality
• weaker light output
• less consistent output
• limited or no camera communication/TTL support
• slower shooting or poor repeat performance for rapid shots
• fewer lighting controls

More expensive dedicated macro ring flashes often let you control left/right sides separately, so you can adjust the lighting ratio instead of getting completely flat light. Some can also act as wireless master units for other flashes.

A very cheap LED ring light may still be useful as a low-cost way to try ring-style macro lighting and learn whether you like the look. But if you want reliable exposure, stronger output, better integration with your camera, and more creative control, the branded macro flashes are generally the better tools.

An alternative mentioned by the community is a ring-flash adapter such as a Ray Flash, which uses your existing flash while keeping its TTL features.