What an indelicate question. Well, of course our answer will be: it depends. There are lots of factors involved, including the client, the project, the working conditions, the country, and many more. We can't just throw a number and that's it.
The price for an Inglorious service ranges from €0 to €2000 a day. Yes, even zero! But unless you can provide something valuable in exchange, or you are an endangered species, it will be higher than that.
So, how much? Well, think about the highest fare you are able to pay. Now think about the highest fare you are willing to pay. Ok, now find the mean and then add some more. That's the price.
It's not a joke, and it's actually quite reasonable if you think about it: