While it is clearly against RCI rules, there are ads for the sale of rci one time points all the time both on ebay and places like TUG marketplace. Unlike selling II exchanges, there have never been any actual reports of anyone being sanctioned in any way, shape or form for selling RCI points. Doesn't mean it doesn't happen or that you can't be the first, just never heard of it happening. Even selling RCI exchange weeks which has much stronger language written in the Terms and Conditions, you rarely hear about sanctions, especially compared to the number of those renting DVC RCI exchanges alone, even when one calls up and reports DVC RCI rentals, it doesn't seem like RCI does anything about it.
So just as non home resorts in SVN and Hilton Vacation Club are expressly prohibited, it seems like until those companies start enforcing the rules, people will do it.
So to the OP, that is something you need to look out for. It's against the rules and you might want to make sure that if RCI starts enforcing and you do not get the points you paid for, there is a clause that you will get you money refunded. On the other hand since you now know it is against the rules can you have an enforceable contract that is predicated on breaking the rules? Will RCI decide not only to refuse the transfer but will they decide to make an example of you and close both your RCI account and the seller's RCI account without any refunds.