I am looking to buy SSR for the first time right now and the info I got is from Disney for SSR you get a $13 per point credit for 100 points, that goes towards your down payment.
The two companies that the resellers used for financing have stopped lending currently and they do not have other finance companies to recommend. I am going to buy through Disney since the finance rate is pretty good compared to a personal loan rate, and you can pay it off early with no penalty.
Hope this helps you out, I am not sure if the incentives are the same for add-ons, but it shows on the finance sheet they sent me so it should be.
Anthony