This is summarized as best I could, but if you want all of the gory details (including proof of the offer and the used listing described below) they are at: Focus Camera
I took advantage of the Panasonic Trade Up offer on the DC-G9, but actually it is Focus Camera that took advantage of me.
I first filled out the trade in form on their web site. They responded by email within a day, but there was no quote for the mint condition DMC-G85 I planned on trading in. When I responded to the email asking for a valuation, I received a phone call later that day.
In that conversation they valued the camera at US$650.00, and that they would offer me 70% of that ($455.00). But a week later after receiving the camera, they offered $300.00, telling me that due to the popularity of the promotion, the value of the camera had dropped. I told her that was unacceptable to me and to return the camera and I would send them something else.
She then asked what would it take to complete the transaction as is, and taking them for their word that the G85 did in fact depreciate, I suggested splitting the difference ($375). 4 days later she contacted me with acceptance, and that they would credit that amount to my card (which they did).
However... a few weeks later I see a "like new in box" G85 in the used section of their web site (exactly like the one I sent them), for $699.99. So it seems the G85 didn't depreciate like I was told, and in fact, they were selling it for $50 more than the original value they had quoted me.
Long story short... they refused to even acknowledge the pricing discrepancy, and just repeated over and over that they credited me what we agreed upon. And now they no longer respond to my emails.
I feel they had intentionally low balled me after receiving my G85 so they could strike some kind of deal where they could acquire the camera for less than it was worth, and it clearly worked. Pass it on!