What Does "Reasonable Offer" mean?

"Reasonable Offer" depends on the item for sale. Someone asking $15K for a non-titled rusted out vehicle isn't priced right to begin with IMO, so a reasonable offer might be 20% of asking price if you have the stomach to take on such a project. A set of brand-new performance heads priced 20% under retail cost has less wiggle room. I always price items at pretty much what I'll take and say so in the ad to set expectations. Doesn't always work but takes bottom feeders out of the equation. If I think something is reasonable priced and what I'm willing to pay, I usually don't try to haggle too much.