Both sxeensweet and slappy are correct that it will expire at some point, but that is still 27 years away for BCV. Disney offered OKW owners the ability to extend their ownership for a few dollars/point from 2042 until 2057. It is possible they may offer that to other properties in the future.
You mentioned having to sell SSR to buy BCV via resale. Why? You can buy BCV direct from Disney as well. Even though Disney designates a particular property as "sold out", they always have points available. Even if they don't have your Use Year available, if you tell your guide that you want x number of points with the same Use Year, Disney will simply exercise their ROFR on a resale contract, and sell the points to you.
If you are talking about saving money from resale, well, then yes, that is a savings over buying direct. Just remember the caveats that you cannot use the points for certain things when buying resale.