That's not a horrible deal. My situation was similiar to everyone else's (BGLOD). My offer was based upon the estimated repair cost by the technician. The repair est was $738. I was told they would pay half of cost for repair. My technician told me they would do that and to tell them that is not good enough. They came back with the offer that for full repair price ($738) they would ship me the new 2010 model 65838. That included everything (tax,shipping,haul away). Again, my tech had told me they would do that. He pointed out, and this is key why everyone should take this deal, the older models are really only 720P/1080i. The newer sets are 1080P. Also, the newer gaming systems, such as PS3 and Wii don't look right or have the correct connections.
So, your $800 is not terribly out of line. Maybe on the higher side, but still decent. It appears everyone gets slightly different offers based upon original purchase price, previous repair history, previous model, etc.
I know I originally only paid $2200 for mine back in 2005 (floor model), while many other people paid over 3K and 4K, depending when they bought it. They are the ones getting better deals on this replacement program. Also, previous repairs are getting lower priced replacement deals.
Bottom line, for $738 I got a new diamond series 65838 and LOVE it ! Just pay it, you won't regret it. Besides, how are you living without TV for 4 weeks ??? My kids would be driving me nuts !