Can an accepted offer be a lowball offer too?

Why would I return an item if the SELLER has regrets?

Because evidently you have regrets too, as the buyer.

I made an offer on something, paid promptly, and received the item which as not in the excellent condition as advertised. I mentioned that and then the "lowball" word came out.

It seems that the seller was not happy with the price, and the buyer was not happy with the stated condition.

Were you trying to renegotiate the sale price after the fact due to your regrets about the condition?

Something different but not too far from the subject. I once bought a piece here, paid for it, received it quickly, condition was as stated, everything worked. Then in a few days I got a message asking me to sell it back to him for the same price. I politely refused. Later in about a month I got another message with the same request. Both messages were short and polite, no explanation was given. This time I decided not to reply. No more messages. He did sound to me like he very much regreted selling it but for whatever reason had to. For some time I felt like sh-t a little bit about this story but then got over it. Still, there is a residue.

"Were you trying to renegotiate the sale price after the fact due to your regrets about the condition?"

In a word, NO

The condition issue was regarding a wooden cabinet, which I was able to correct myself using steel wool and some refinishing products.

If you take a low ball offer its your own fault.I get many jerks that offers less than half of my asking price are they joking?? 

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.