Question about taking on a commission—who has to buy the pattern?

I have a general question about taking on/assigning commissions

If someone finds a pattern on Crazypatterns that they like
and would like to have it crocheted/knitted/sewn because they don’t want to or can’t do it themselves

should they first specifically contact the person who created the pattern and ask whether that person would make it for them? For the sake of fairness, so to speak?

What if the person who created the pattern isn’t available to make something from the pattern,
but someone else is willing to do it
do both people
that is, the person who crochets, knits, or sews from the pattern
and the person who wants the finished item
each have to buy the pattern separately?

Or does the person who wants the finished item basically pay for the pattern twice, or is it enough to buy the pattern once in total?

I’m afraid I’ve worded this a bit complicatedly
but I hope what I’m trying to say comes across
 

And one more question

if someone buys patterns
and then wants to sell
items made from those patterns, is that person allowed to offer them for sale here on the forum?

The pattern descriptions each say what you’re allowed to do and what you’re not allowed to do
Does that mean there’s no general rule, but that the individual rules set by the respective poster must be followed?

It depends on what the seller allows. If there’s a statement about this in the item description on the product page or in the seller’s terms and conditions, then you have to follow those rules. If there’s no mention of it in the terms and conditions, the item description, or the patterns themselves, then you’re allowed to sell the handmade items (one-of-a-kind pieces).