This comparison took a hard look at five portable remote callers in the $400 - $600 price range. The lineup included the Foxpro Fury and Foxpro CS-24, the Flambeau MAD Bandit, the WT 2030 MS, and the Kanati-Tek CX-1H. Four of the models can be purchased at AllPredatorCalls.com and the fifth is available only from Kanati-Tek directly.
Update Feb 2014:
This article is becoming dated. There are quite a few new or upgraded callers from FoxPro and several new callers from Mojo, ICOtec, Primos, Flextone, Hunter's Specialties, and Extreme Dimension. Minaska and Kanati are basically out of business. Buying all of them and testing them is beyond my current interests or budget.