Agree -- I don't understand how they can get $150 for it, especially when fully loaded resale contracts are dropping under $100.
That said, if, despite all the downsides, one decided they just had to buy at Aulani becasue they want to go there most of the time with their points, there is no reason not to buy resale. The only benefits you get by buying developer points is that you can use your points for the Concierge and Adventurer collections -- and other stuff that's a horrible use of points. Resale Aulani points are exactly like points bought direct for use at Aulani and for use at all the other DVC resorts.
Still, anyone thinking about it should wait a couple of years. Aulani points are going to keep going down. You shouldn't be in any rush. Try renting there for a couple of years and see if it still has its luster. Don't buy there because you go for a week, one time while your kids are the perfect age for the place, and you love it. And don't buy because you get convinced that you can use the points for cruises and stuff -- it's a horrible value.