I think you have the classic audio internal debate. And the old law of diminishing returns rears it's head, as well. Is the Denon 6 time better than the entry level Insignia and other units for $300? Nope, no way, Jose. Is it twice as good? MMMMMMMMMaybe. I would hope all internals were of higher grade quality, dacs, caps, wiring, vid chips. Most here are waiting for the Oppo player to come out at $500 ish dollars. I, personally am waiting for the LG Blu with streaming Netflix capability myself.
I'm not married, but if you was smart about it, you'd make sure your sweetie pie was aware of your inner struggle between the $1700 unit, and the $500 unit. That way, when you buy the $500 unit, you look like a star...........and a good spouse. Smiles.
Have you asked yourself all the right questions on your Denon purchase? How many movies a week do you watch? Are you sure the jump in picture quality is worth that much to you? Are you willing to invest in a format that isn't sure to be around for very long? Is there nothing else in your system that would better serve a $1700 investment?
(Like a subwoofer, or new front speakers.)
Just checked on ebay, and the 2500 model is closer to $800. The 3800s were going for under $1500 shipped, so there are some deals out there...........good luck!
Now, if you make $300,000 us a year, buy the Denon and make yourself happy.