if you look at the henchmen cost it is way overpriced. it should be like wizard101 were the lvl number is the cost. and once its over 50 (where it started) you can get it a bit more than the lvl. i mean lvl 20 is 75 crowns, thats just, well ... wow. if you agree with me post so KI will lower the prices.
Haven't tried the upper level Henchmen yet. The first level of henchmen seem to be appropriately priced for their abilities and the fact that you can use them (apparently) in only one fight.