The machine has chew marks on it from someone opening the case improperly in the past. It also has a noticeable deep scratch in the front plastic, just about the CRT. It is also admitted that some of the keys stick.
This auction is similar to other auctions I see from time to time. So there is nothing too extraordinary about what is being offered here. It's not like it was used by Steve Jobs himself, which would differentiate it somewhat from other Mac 128k auctions that also offer original boxes.
I also took note of one of the comments at the bottom of the listing which states the following:
"Was this the one that had the wild commercial?"
If that is the mentality of would-be bidders, then it will likely sell for a high price. But that won't mean it is necessarily worth such an outrageous price. People who don't know much about what they are bidding on tend to drive the price into the stratosphere. (e.g., "Oh my, it's THE product related to that commercial which I never saw myself but have heard a lot about. OMG, this must be worth $3,000 these days.")
I myself picked up an original Mac 128k kit quite similar to this one, sans the outer box though, for $450 plus ocean shipping to me in Japan. That included a 512k logic board too, as well as an external 400k floppy drive. No sticky keys, no discolored spacebar on the keyboard, and no screen burn in. It included an amazing amount of boxed 3rd party software too, including Microsoft Excel, Multiplan, CopyIIMac and ProVue 2. It even included 4 boxes (2 unopened) of Apple branded 400k floppies. That was a few years ago, but the point is that I go that price because I was competing with others who pretty much knew the value of what they were bidding on. The price was not artificially jacked up by ignorance. That's also why I picked up my HyperDrive20 Mac on EBAY for under $100, plus shipping to Japan.
So as always when bidding on auctions like this, be careful. Note well the mentality of other bidders by considering the comments at the bottom of the listing. And one would do well to consider how much the machine will ultimately go for by reflecting on the the fact the current price is $560 but still with 6 days to go!