I'm certainly not the most experienced person that can reply, but I think the sales people typically play down the transferring or “renting” points options. After all, they want to sell you as many points as they possibly can. Different DC members have different ideas as to the minimum number of points required. As for me, I'd buy something like 1,500 or 2,000 and then rent the rest. You can always buy more and add them on later.