@TravelTime to expand upon above comments: If you want regular access to NYC, or July, Aug in Oahu, or ski weeks, you should buy platinum units at those locations. Of course buy resale.
If you are more flexible and want to trade around the system, points are points in the HGVC system and you want the least expensive cost per point. Suggest start with buying 7000 points in Vegas (Blvd, Paradise, Flamingo, Elara properties run 7 - $10k resale except for Flamingo which could be as low as $4000 because there is no ROFR; about $1 per point - avoid Trump which is much more expensive) and use those points to trade to Hawaii or elsewhere.
Alternatively 7000+ point Bay Club units on the Big Island if you want a lower buy in price ($1 - 2K) but slightly higher MF. You will need to run a breakeven depending upon how long you intend to own.
Scotland is currently a good deal but you could be stuck with currency fluctuations which may flip this equation. I believe those properties are RTU in perpetuity and not deeded.
Good luck!