I agree that relying on one study can be risky. Howerver, I don't see much incentive for ARDA to lie here. The study ends up saying that more HOA-Controlled resorts should have resale programs. How is that to the developers' advantage?
And, IIRC, the study was done by academics, not ARDA employees. Not a guarantee of honesty (let alone accuracy), but it is some protection against fraud.
Also, let me relate my personal experience with one of my resorts. I asked if they could help me sell my week. They said yes, they work closely with a realtor who helps owners sell their weeks. Well, I called the realtor, and they charge a minimum $2,000 commission, and require an exclusive listing agreement for a minimum of two years! I have been trying to give away this week for over a year. I've found no takers with a $0 purchase price, and weeks like mine get no buyers when listed at $0 on eBay, so I'm very skeptical of any realtor's ability to sell this for $2000. (There are some fixed summer weeks at this resort that are worth real money, but mine is off-season.) If I listed with this realtor, then finally found someone to take the week for $0, I'd owe the realtor $2000.
I also have a week at a second resort listed right now for free w/free closing, on the TUG bargain board, no takers. Again, the resort has a realtor for owners who want to get rid of their weeks. Here, the fee the owner has to pay is $500. That's a more reasonable fee, but since my MFs are less than $200 a year (I own an every-other-year week), it's still not worth it.
A third resort where I owned works with a realtor who charges about $470 to owners who give a week away. I was able to give my week away on my own, paying only about $125 in closing fees instead.
I suppose all of these resorts would say they help owners sell their weeks, but I wouldn't call it very helpful.
I do own at another resort that lets owners list available weeks in the quarterly newsletter, for a fee of about $25 per issue. That's more helpful, although still a bit pricey if a takes a year or more to "move" your week.