Being able to leave a follow-up comment is nice, 
but when someone is flatly leaving negative 
feedback just to "get back" at another user that 
didn't let them do something like cancel a bid, I 
wish Ebay would deal with it the way it SHOULD be 
dealt with -- REMOVING the inappropriate feedabck.

Or another option would be, once a seller goes 
through the whole of the non-paying bidder 
process, it would be nice if only the SELLER 
could leave feedback for the transaction. (The 
bidder didn't pay -- who cares what the bidder 
thought of things? If they have something to say, 
it can be left next to the negative feedback in 
their file.)

But that doesn't help you in your dilemma. If you 
state somewhere in your auctions that negative 
feedback will be left for non-paying bidders, 
then I would say to definitely leave the neagtive 
if the bidder doesn't pay up. I would also see if 
you can fit it into the 80 words or less that you 
were threatened with retalitory feedback.

As someone else with a 100% positive rating, I 
hate dealing with ANYONE who starts acting weird, 
just in case they're one of Ebay's far too many 
problem children. BUT!! Keep in mind that *every* 
good user on Ebay knows it only takes one idiot 
to wreck a 100% positive rating. (And that now 
you can't even wait for that person's inevitable 
banning to have your negative removed.) I don't 
know of any sellers who ban people with negative 
feedbacks anymore. For a seller with negatives, 
so many will actually point out in their 
auctions: "Yup I have a negative. Ebay has idiots.
I also have hudreds and hundreds of positives." 
Then, I can't remember who it was, but there was 
one seller with a link to a *great* page she made 
explaining, in detail, every negative feedback 
she had, which ones were ratalitory, etc. . . (I 
wish I could remember who it was so I could show 
you, it was that level of great.)

So as much as you don't want one, a negative 
isn't the end of the world. And besides, these 
jerks have probably done this to numerous sellers 
before them, who were cowed into not leaving a 
negative, and thus this person gets to go on with 
no problems. More than that, the next deadbeat 
bidder might take a look in your feedback and see 
the negative followed up by your calm comment 
of "well, the person decided not to pay". And 
said deadbeat might decide to go find another 
seller that's easier to annoy. . .

Of course, I would save their e-mails and report 
the threats to Ebay IMMEDIATELY. Because threats 
aren't allowed either. ^_~  If you're risking a 
negative from them anyway, you might as well have 
fun with *REALLY* trying to teach them a lesson.

Many Sharp Smiles,
--Drac