Are you looking at the 36SFD? New, it's stickers in the low $150s, so a good deal (new) would have been in the low $100s.
Here is one (sold new) to get an idea of what they went for:
New Monaco Monarch for sale in Alvarado TX | 2012 Monaco Monarch For Sale W/Full Wall Slide & King Bed 36FSD Class A For Sale from Motor Home Specialist in Alvarado Texas
Depending on how much the dealer wants to move this unit, I think a decent deal would put you in the low to mid-$80s range for just the price of the coach when all is said and done. If you can get lower than that, it would be a complete steal. (Remember you have tax, tags, etc., etc., so factor that in to your budget as well.)
Keep in mind, depending on when built/sold, that 2012 may actually have been bought and used all throughout 2011, so realistically it could have 2 years of use on it by now too. Use that as an additional bargaining chip.
Good luck and let us know how you make out!