Actually you should be able to get better than 25% off list, as this is a 2006 leftover. The factory has been making 2007's since spring '06. Try to negotiate down to invoice or below (I was shown the invoice on my '07).
Depending on how long this unit has been sitting on the lot, be sure to have oil/filter changed, and check battery performance. If the unit has been on the lot for over 180 days (possibly could have been on the lotupwards of 360 days by now) I would negotiate for new batteries as well, as I am sure the unit has not been driven much, and not been plugged in to AC to charge house batteries as well. Once they go dead, they no longer hold the charge as they did when new.
Good luck on your purchase.
P.S. Don't get frustrated by all the 'Punch List' items you will have to deal with after the purchase. This is standard operating procedure. Once you get your coach tuned, you will really love it.