is it under or off the rules to offer my services about paracelsus stone?

the question is: i have one and i have no mythics (the necrolocks were not nice to me) and i dont want to spend the stone in a legendary item but can i (i mean if its under the rules) to receive some kind of payment to receive a mythic item, upgrade it with my stone and give it back to the owner of it?

thx in advance