I got one the othe day on a $45 item. It was submitted at $18, immediatly retracted as wrong amount and re netered as $8. I declined and they reoffered at $6. This on free post items that are going to cost $7 to post.I blocked them.

Aything 50% or less I decline without counter. Anything under 20% I often just block them, if I can be bothered.