Condition and originality are everything.
An early high polish will go for $1500 or more in excellent condition, or $300-400 in fair condition.
The later ones will typically be in the range you mention.
I wouldn't expect them to be any cheaper if you could find one at a show.
The Type II is the hardest to find, it has the barrel bushing and shorter barrel.
Always take a good look at the bore as these tend to have pitted or worn barrels esp in the earlier ones.
I will mention that there are good deals out there if you know what you're looking at and are willing to dig... I found a nice Type III Hi Polish on GB for $500.
That is the exception rather than the rule though.