Is it worth adding low quality images of rare items...

…when better images are not available.

By low quality I mean images such as thumbnails which are scaled up, low resolution, blurred, or partially obscured. 

Detail on the images would need to be clear enough to illustrate the coin or banknote in question.

Naturally, any such images would be from permitted sources, or member-generated.

Something is better then nothing, also bad quality pictures seem to irk people more then missing ones so they replace them faster in my experience. But it could also be that if there is at least one picture the chances are higher that there are more then when there are no pictures to begin with ¯_(ツ)_/¯.

Hibernia

Is it worth adding low quality images of rare items...

Absolutely, as they say, “a picture is worth a thousand words” better a poor image than no image.

Idolenz

Something is better then nothing, also bad quality pictures seem to irk people more then missing ones so they replace them faster in my experience. But it could also be that if there is at least one picture the chances are higher that there are more then when there are no pictures to begin with ¯_(ツ)_/¯.

Yes - a bad picture sets a challenge!

If it discernible and does not oppose any other rules, then yes.