Everyone ... thanks for the thoughtful replies!
@Dlanor Sekao - I am too afraid of the deal itself going south. eBay offers excellent protection for buyers. My concern is more about the quality of goods: grey market, import, unmarked refurbs, past returns, etc. The discouragement was more about the most recent negative feedback was about a K-3. Why couldn't it have been a Nikon or a Canon?
When I searched their feedback for "k-3" I found some positive transactions as well.
@Rupert - You bring up a very good point. In general we get what we pay for even if it means we something intangible, like a peaceful transaction vs. one fraught with stress. That's got to be worth something. Plus, purchasing from them could help support PF. That is worth noting too.
@Imp - I do indeed have two very nice 50's, a FA 50mm f/1.4 and a D-FA 50mm f/2.8. The DA 50mm would either be sold off after the return period expires or I would give it to my father as part of his birthday present in April. You reminded me about the extended warranty. I completely forgot about it. Excellent point!
@ramseybuckeye - The 4% is nice and if I count the 1% cash back from my credit card then I have 5% total. I do have some eBay bucks but they pale in comparison to Adorama's 4%. The 1% cash back from my credit card due to the PayPal transaction would also also be small. All of that would have to be balanced with the overall package and transaction.
I have to confess that my eyes have been wandering to other systems - more for fun than for seriousness. One of my forays took me to DP Review's Dynamic Range Widget. I downloaded RAW image files for the K-3, K-50, and the A7 at ISO 100, 3200, and 6400. Obviously, both the K-3 and the A7 run circles around the K-50, especially at higher ISO settings. I did not find the quality of the A7 exceptionally superior to the K-3. There is less noise due to the larger sensor but the K-3 resolved more detail. Very surprising. I expected the A7 to resolve more detail. The corners in the K-3 samples are softer but I believe that has more to due with the lens than the camera. I feel unshaken in my dedication to the K-mount system. If the K-3 can really improve my experience with my FA Limiteds (resolving power and AF) then I see myself with two K-3 purchasing decisions. They are "good" and "better". Now all I need to do is a find a "best".