Re: Which mandolins should I be looking at in the $2000-$4000 ran
In Europe consider The Acoustic Music Company (I linked to their Used/Vintage section). Trevor, the owner, posts here and has a very good reputation and currently has an amazing selection. Of the models you list, I have played a Collings MT and it was a powerful instrument. Collings are also renowned for consistency of product. While I haven't played one, many people have been very impressed with the Gibson F5G.
There are two things to aim at in life: first, to get what you want; and, after that, to enjoy it. Only the wisest of mankind achieve the second. Logan Pearsall Smith, 1865 - 1946
+ Give Blood, Save a Life +