Speaking of books, I recently purchased the
DVC Field Guide put together by Jimmy Shaddock
https://www.dvcfieldguide.com/ and found it to be super valuable. On his website he also has availability tables which can really help answer some of your questions as to what may be available at any given point in time, which I find more useful than the blanket statement of "availability at 5-6 months isn't bad". It depends on what time frame you're looking at for your visit.
I bought a loaded contract resale, 250 pts with 180-ish from the previous year. Work intervened with my planned usage and I will end up using something like 140 points this use year which left me with 290 points that I rented out. Renting out 290 points ended up covering more than 1/4 of my purchase price, or a few years of dues if you want to look at it that way. Of course renting out points is not a guarantee but it's at least useful to know that the option is there.