Thanks for all the nice language - very mature indeed...
I based the 1500 euro GUESS on what I know friends of mine charge (equivalent a/c) per day for short term deals (like one to three days) on short notice where they get to reposition themselves to where the aircraft is at their own expense and on what I charge per day in a contract deal that's more long term in its nature.
I also stated that the cost per day would decrease rapidly if some kind of longer term contract could be established (although some didn't read that long as it they rather spend energy calling other people stupid).