Well...here we go again. Problem is, now we are comparing apples to oranges so to speak. Here's my two cents worth....
On the basis that this car IS a real King Cobra (assumed), it would seem a fair price assuming (once again) that the body is VG to EX condition as it appears. Certainly, I would expect there will be some interested bidders, in any case, just on its high vis appearance. It's probably "worth" around the price, just for what it is (a King) and whats been added to it, if thats what one is looking for. It is a nice looking car, that would look nice in my driveway! However, the reserve of 6500 with an opening bid of 5K will keep some potential bidders away. I wouldn't expect LOTS of different bidders willing to start that high.
The biggest potential drawback to getting numerous higher bids on this car, is the fact it is modified. Not only does this become a riskier purchase than say (a car like Sal's CobraII), but it is usually viewed as a detraction on a car that might otherwise sell rather easily, on the merit of it's relative scarcity or rareity, as in the case of a King Cobra. So, I would expect this to also narrow the field of potential buyers.
Personally, in an apples to oranges comparison of the cars (Sal's Cobra and this King), I wouldn't be sold on making such an offer based upon the few pics that are in this listing. I'm not (for example) nearly as excited about the performace potential when viewing that particular engine bay pic, as I would be in believing the "originality" of Sal's car based upon the outstanding attention to detail shown in the pics of his stock engine.
I wouldn't expect this car to sell as quickly or as high as Sals either, despite the fact it is a King Cobra. "Originality" seems to be an especially important attribute to buyers of King Cobras in particular, as opposed to other II's... and a few thousand dollars more would likely fetch a King in as good an overall condition, without modification.
I think Sal's Cobra sold for what it did, based upon its workmanship, and attention to detail, in a pure stock restoration effort.... that usually helps command a price on the higher end of the scale. While not a King Cobra, his II represented an affordable "special package II" that seems to be gaining in popularity. I'm sure many viewed his car in that regard, and bidded accordingly.
Bottom line...both cars worth decent bucks in line with asking prices, for different reasons. King possibly has more potential overall value, but only if restored to stock. Congrats Sal, on your work in restoring a car that brought a respectable sale price!