That is definitely more than expecting but at least I have some numbers to work with, and I do understand that greater quality will demand a greater price but this "middle of the road" estimate is very helpful.
Also it might be worth to think about just buying models and/or graphics for some of your assets to reduce the costs. After all a lot of fantasy-weapons tend to look the same or at least very similar. The same goes for some GUI-elements such as health-bars. For enemies and especially bosses (and tilesets) you will still want to custom-model it, as this will make your game look more unique compared to other games of the genre.
Buying models and images will likely prevent you from applying a very unique art-style but the reduce in cost might well be worth it.