Can an accepted offer be a lowball offer too?

There seem to be two different issues at play here as I read it, first seller regretting selling something too cheaply and I concur that's on the seller for accepting a two low price in the first place. The other issue, receiving something in less than the condition promised is totally different. I will say as a seller I never misrepresent my equipment, however despite that I guess not all people see something the same way. I have twice had instances of sellers mildly complaining, one over an interconnect that looked used, it of course was used, and for not including a original box with an item when i never claimed to have the original box. As a seller who jealously guards his reputation and feedback my first inclination in both instances was to offer to take the item back for a full refund. I would hope in the event of a grossly misrepresented item or a misunderstanding over an items condition the seller would do the right thing and try and work something out with the seller. Low or not an accepted offer is an accepted offer and a valid contract so to speak.

I've never been asked to take something back but I have preemptively offered at the inkling someone might be dissatisfied was what I was trying to say. Both times i offered the buyer elected to keep the item in question.