Maybe it's me but I can't even find the auction any longer. As a normal you can still find the auction even after it ends. I was wanting to see the complete bid history.
Here is the direct link https://www.ebay.com/itm/364578300452 The top two bidders (winner and underbidder) have many retractions and a fairly high bid percentage with this seller. I have also bought from this seller before and did not think anything odd was going on with my auction win (coin arrived and seller was good). Since the final price is much higher than a 1964 Kennedy rattler goes for (about $100 seems closer to reality based on prior sales) and I don't have doubts about the seller, I would be more inclined to believe that the two bidders ran it up for some reason (maybe to help sell their own coin). We might see this one reappear for sale as the winning bidder could not pay.
I'm naive here. Is the holder that is running up the price? I've mentioned before, I think there are games being played with insider bidding going on with some of these auctions, friendly bidding wars if you know what I mean. Hell, I've got a bunch of MS 65/66 or better 1964 raw Kennedys. Maybe I should get them graded and join the war.
The rattler holder (from the 1980s) is the factor in the auction (although it went above what those normally bring as well. In a new PR 65 holder, this would sell for $25-$30 on average. In a rattler, you could see around $100.
My next question.......why are these getting graded anyway? Is it dealers sending them in bulk getting a big discount on volume???
It's actually legit and rare. Not THAT rare, but there are surprisingly few "cheap" coins in rattler holders. As to why? Maybe some dealer wanted to see a real, production example and sent off a couple of cheap coins as a trial.
If you are asking why did these get sent back in the 1980s, I would guess it's what Burton mentioned above or someone insisted on having the coin graded (authorized dealers had to send coins in for the majority of the public well into the 1990s before PCGS allowed direct submissions from everyone). If you are asking why someone would send these in now, then it could be a bulk rate for dealers (they send dozens or even hundreds and pay under $10 each-a few nice grades pay for most of the bunch-or it goes to the tv shows/advertisers). Also plenty of people send in inexpensive coins all the time; it can be for sentimental reasons, hoping the coin is a higher grade, just not knowing, or even needing an extra coin to round out a submission.