There aren’t rules against it. Just absolutely be aware that it is 100% UNSUPPORTED.
What that means is that if it goes south, you won’t get your gold returned to you. It also means that if the person you’re receiving your gold from on Westfall is giving you illegal gold? You’re putting your account in jeopardy.
We’ve had so many suspensions and bans due to these kinds of transactions, I can’t even fathom a good estimated number at this point. Even your bestest friend in the whole world giving you gold does not mean that you’re safe. Just because you don’t know that the gold was gained illegally, does not mean you’re safe.
You’re going into an extremely high-risk transaction - period. It doesn’t even matter if you’re finding someone through one of the Discord servers that has ratings and reviews - there have been people who’ve gotten burned from those just as easily as they have any other source.
[Editing to link some relevant threads with SFA responses.]