Garnet, ... The context of of SKath's statement was retroing to get to Five Star Elite.
To retro staroptions from a purchase on the secondary market so that they count towards Five Star Elite, you also must make a developer purchase.
SKath's conclusion is to buy on the secondary market at Kierland and then buy from Starwood at Lagunamar and retro in the Kierland staroptions if you want to get to Five Star Elite. (I agree that Lagunamar is probably the place to make the Starwood purchase. I, personally, think it is more desireable than Desert Willow - which is selling at a comparable price. But whenever you buy from the developer, it's not really based solely on economics.) However, if all you care about is retroing staroptions to get to Five Star Elite, you can buy 148,100 staroptions cheaper at WMH or SDO than at Kierland. But, Kierland has other advantages.
The "traditional advice" is to buy at Kierland because it is a mandatory resort and the cheapest staroptions available at a mandatory resort. The mandatory staroptions can be used/spent at any Starwood timeshare. There is no need to retro them. And, the value at Kierland may hold up better than a comparable staroption timeshare at WMH or SDO because of the mandatory nature of the resort.
But, I also believe you should buy where you want to go in the season you want to go there. Kierland has wonderful amenities, is inexpensive to get to, is located near/in a large metropolitan area, is warm in the Winter, and Kierland has relatively low MF. Thus, even if you never retro the purchase to get to a higher Starwood elite status, Kierland is a popular buy for TUGgers. I bought there myself and retroed in the 148,100 Staroptions when I later bought at Lagunamar. (Same procedure with my 196,900 options from my Harborside secondary market purchase.)
It was not the absolutely cheapest way to get to Five Star Elite. Overall, for the money spent, I am happy. ... eom