Well, I rather dislike buying anything from ebay (during last few years at least), but I would have very happily placed a bid for $200-300 for that kit!
The rigid summar is rare and valuable. I missed the fact this one appears to be in chrome. The elements look to be in reasonable shape (from what we can see looking into the "well"). Of course, it can be hard to tell when not in-hand, but I saw no obvious deep scratches on that front element - and most summars have....um....front elements with plenty of "character". Also, the barrel looked like it had not seen much use in its life.
If the elements are in good shape and haze (if any) gets removed, the summar can provide really neat images. See some of the images Erik has made (somewhere on RFF).
I happen to have a black-rim summar with a really good front element, but it has some haze and the internal black paint is flaking in places - so the images aren't very good. Its a lens that wants to visit Don (DAG) some day.