Droste, that is going to be typical for most places. It is an administration fee for them to process your application. It doesn't come for free you know. I had to do the same for Bristow, as far as I remember. It was a while ago now.
Application fees are somewhat different to a deposit though, right? I just got my green card this year through marraige, and if I had not passed the interview I would have lost all of my application fees (and lawyer fees).