What is this problem/plague on coin

Exactly.

$380 is not a bad price at all. I have been hunting for a cheap SP69 for a few months. I have seen SP70 go for between 380 and 700, typically closer to 400 for the better deal. Some crazy people out there pay 700 for this PCGS/NGC coin on heritage and other sites, when they are readily available with BIN for hundreds less at other sites in the same holders. Takes about 5 mins to do a though search, so it beats me... I watch for these coins on ebay, Heritage, GreatCollections, Collectors Corner, and Teletrade. You did not pay a bad price, in fact, its one of the better prices I have seen, but that may have something to do with the toning.

Personally, I am looking for an SP69 which go for $150 when they are cheap, and ~$220 when they are not cheap. So, its a big spread for one grade. If you really hate the toning, maybe return it, pay a little more for a perfect 70, or save a lot money and get a perfect looking 69.

Hope this helps.