This post caught my interest because I bought a 2BR triennial unit from a developer (full price - didn't know about TUG then) and am in the process of doing a DIY upgrade. I am in the process of buying another triennial unit at the same location on the resale market (which is a really good deal). The second one is a 3BR unit in a better week (more points) at a newer and better resort in the same resort group in the same general location. Let's hope this new deal falls into place. So basically I am upgrading myself and now I either need to keep the first one for a while or try to sell it (or give it away) later.
I am going to this location maybe this summer, but more likely next year. I suspect they will ask me to attend an "owners update" and try to convince me to upgrade. I still am interested in upgrading further, and I want to find out what they have to offer and how much they want for it. I want to find out whether they will take both of these off my hands in return for something else (such as a biennial instead of two triennials - or maybe put me into another type of 3BR unit that is worth more points). That would give them 2 units to resell. (The same developer is selling units at both of these places.)
They might surprise me, but I strongly suspect they will not take an even trade. If they are willing to make an upgrade deal for what I otherwise would have to pay to unload the first triennial, I might just go ahead a do it. I have a general sense of what is would cost me to give away the first 2BR triennial. If they want too much, I won't do it, and you'll probably see my first unit in the TUG bargain basement. Even though I might be interested in an upgrade, I still would be very happy with the second unit I am buying.
The only advantage I have (if it is any advantage at all - probably not) is that I have 2 units to trade in.
If I had only one unit to trade in, I would not even hope for a good deal from the developer for an upgrade. They are likely going to ask too much. This would basically be the same thing as buying a new unit from a developer with some (emphasizing "some") credit for the prior unit. If I had one unit and was doing an upgrade, I would be very surprised if they gave me full credit for what I paid them in the first place.
There is only one way to find out. Go to the presentation, ask them about it and see what they say. If the price seems too high, you probably could save yourself a bunch of money by buying your own upgrade on the resale market (assuming what you want is available - you might have to search the listings daily or weekly for one to pop up). You might even find a free one. Maybe the best benchmark is to figure out how much it would cost to give away your current unit and pay the closing costs, and then convince yourself that you would not pay the developer more than that.
If anyone on this forum has paid a developer to upgrade, perhaps you let us know what your experience was like. Don't be afraid to admit you paid too much. I certainly did with my first unit. We learn from our mistakes and move on.