Then wouldn't an even better strategy be to buy even cheaper resale points from Vero Beach, and then just plan to use them on larger units at 7 months? They're selling for half of what some of the more in-demand resorts do.
We are doing just this!
VB is a great property and owning to use there and at WDW can be a great and viable option, but the long term cost of VB will be more than the long term cost of SSR. At the end of the ROFR for VB, assuming a 3.5% inflation rate, you'd pay as much for VB just in dues as you'd pay for SSR purchase plus dues. Even if you truly invest the difference up front, about the best you could do would be to break even. But you'd have several negatives compared to SSR FOR WDW, you'd have more risk of loss if there were a catastrophe, you would not have the 11 month window, you'd have more risk for dues to increase at a faster rate, you'd have something worth proportionately less best case scenario and you'd be ending in 2042. When I ran the numbers recently I used a $30 pp spread between VB & SSR. That assumes one is not buying a subsidized VB contract, the numbers would be different since the buy in would be more but the dues less.
I also ran AKV & BLT a the same time. I used the same buy in price for AKV as SSR and a $65 spread for BLT. At 2042 both were also considerably cheaper than VB and with those assumptions almost identical in cost but BLT would be cheaper than AKV further in. You have all the differences compared to VB I mentioned above. Each of those 4 properties have advantages and disadvantages owning there. The specific advantages are the 11 month window for each and esp for BLT & AKV, the cheaper and specialty views. IF one bought AKV to use mostly for value AND bought the fewer points, it becomes cheaper at some point than owning at SSR and using for AKV standard. The last time I did the calculation one had to use 2/3 of the points for value consistently just to break even compared to owning at SSR and using for standard view there. The same principles would apply to BLT standard but I haven't run the actual numbers for when BLT would be cheaper than SSR in this situation. Just ball parking it I'd suspect one would have to use BLT 80% of the time or more at standard and buy the fewer points to break even compared to SSR used for Lake View there.
All of those assumptions also ignore the fact you likely would get the cheaper or specialty view at the other resort (value/standard) at some point. The other advantages to buying SSR are there are a ton of resales comparatively speaking making it easier to find the perfect contract as well as to get a fully loaded contract and to negotiate a good price. There is a tipping point where VB would make sense but currently it appears to be getting VB for free or less.
We are currently looking at adding on at SSR for a few reasons:
1) I have now turned 5 different sets of friends to rentals on the boards in the last 18 months because they didn't want to spend the $$$ on BLT or VGF (even with a "friend discount") or we didn't have enough points to rent to them with what we plan on using for ourselves
2) At 7 months, all of our points are worth the same, and I would rather go to a different resort with cheaper SSR points than my BLT or VGF points
3) This diversifies our ownership (I can't help it, I hold a finance degree)
4) If we ever want to stay in a cabin, 3-bedroom villa, bungalow, etc., we should do it on cheaper points than our BLT or VGF because they are usually available at 7 months. Those MK resort points just cost too much to "blow them" all on those higher end accommodations
5) I would love to add on 100 points to our BLT membership, but the PPP is just to high for us right now and doesn't seem to be coming down to what we would pay anytime soon
6) I would love to add on at Riviera once it is done, but we will most definitely be priced out at ~$200pp because we stay in 2-bedroom villas, and the size of the villa is not something my family wants to compromise on just to own somewhere
7) We may stay at SSR sometimes and rent out VGF or BLT for a decent profit because we bought them at a somewhat reasonable PPP
There are other reasons, but this is the short list.