My mom told me recently that I could go harvest Strawberries from a field and pay for each Kilo I harvest, but while I am harvesting I am allowed to eat as many strawberries as I want. I somehow still feel like this is not legit and there needs to be some sort of miscommunication.
Well, you are essentially paying extra in terms of the time involved, so I suppose it wouldn't be too surprising that some places might allow you to do things like eat along the way since you can only eat so much in a sitting :)
As a Linux user I forgot that time is something valuable. But now I believe more what I got told.