We need a rule that if the person who is selling something doesn't say "first free", then you can't ask for it. It's SO annoying to look at almost every tutorial being sold, and someone always asks for first free. And sometimes they even ask when it says "no discounts".
It's up to sellers if they want to give first free, i don't think it should be made a rule really IMO.
A rule won't do much. The only thing you can do is -rep them if they get too annoying and if they complain, come to us.
I agree with BlackFuse A such rule where mods will have so much more to deal with too, because alot of people do it.