Problems seems to be:
Westgate - The majority of people on this board hate Westgate and wouldn't take a timeshare from them for pennies on the dollar. I value their insight.
Developer sales - Speaking of pennies on the dollar, that is all you will recoup if you need to sell down the road.
Developer incentives and guarantees - I don't care what goodies any of the developers offer down the road (and it sounds like Westgate isn't offering any), just know that incentive programs have and will continue to be modified or eliminated. The cash savings buying resale simply outweigh any advantages from buying from a developer.
Substitute used cars for used timeshares (because all timeshares are used regardless of who you buy from) and look at it this way: You want to buy a used car. The guy down the street originally bought the car used (because all timeshares are used) for $20,000 and will sell it to you for $5000. The dealer who originally sold the used car says they'll sell that same car to you for $20,000 but will offer free maintenance on the car, free car washes, free loaner cars, free insurance, free whatever . If you could get this promise from the dealer in writing and they put up collateral that you had a lien on with the understanding that if the dealer defaulted on these promises, you would have the collateral to recoup some or all of a specified amount of the loss you suffered on the default (just like they do when you finance something from them), then you can try to determine what the present value of these benefits are and determine whether they're worth $15000 or more. The problem is the dealer doesn't do this. The dealer reserves the right to end or modify these promises at any time and has no obligation to provide you any compensation for doing so. There's no lien on collateral protecting you, you can't affect the company's credit, you can't turn it over to a collection agency, and you can't go to court to win a judgement against them, you simply get nothing if they eliminate the incentive program or change it in such a way that it becomes worthless. There is no way to assign a present value to these promises because there is no way to know if they'll exist tomorrow, and they have to be severely discounted (like almost to zero) because you are taking all the risk. It makes much more sense to take the cash savings by buying resale (not buying from the dealer or developer) because here the risk is clearly understood.