It all depends! A couple years ago when we bought our current MH, we offered $20k less then what the dealer was asking. After a few months of going back and forth, we settled on about $12K less then what the dealer was asking. I think that at the time we got a fair price on it.
Look around and see what the same style MH is going for on other sites/dealers. If the MH is in real good condition and something that you really want, then you may be willing to pay a little more for it. How long has the dealer/seller had the MH on the market? If it has been for sale for a long period of time, then they may be more willing to work on the price.
2009 38' Diplomat
CSM- retired, wife as co-pilot
Reka & Ali providing security (our 2 labs)