These things are always so subjective and regional considerations always enter in, as well. Some models that are common in some parts of the country seem to be more scarce in other areas.
Having said that, there are scads of model 10's out there but in the last few years the snubs have come to be more in demand with the proliferation of states issuing carry permits.
Like everyone else, I love to get a good deal and buy 'em as cheap as I can, but all I know is I have one M10 RB nickel that I would have to be hard up to take less than $450 for and a M10 SB nickel that I wouldn't sell at all because it was dad's gun. Both are in 98% condition.
Around here local prices are all over the map but prices seem to average (for a decent specimen) from $350 on up. Even a blind hog finds an acorn once in a while and I have seen them cheaper, but these days the correlation between price and appearing it has been drug behind a truck at the end of a logging chain has disappeared beyond all reason, at least in these parts. Folks ask those prices for stuff I would call "beaters" and would have been hard pressed to even pay $200 a few short years ago.
Depends on how bad you want one verses how bad the seller needs the cash. Never hurts to start the offer at what you'd like to get it for - it's like asking a girl out the first time - sometimes they say 'yes' . . . .