Wordpress's move to limit features leads to a logical demotion from G on non-https links.
Not all sites are transactional so logically do not require the cert so G can not blanket demote link value.
With this information, we can assume Google will only ever (let's just say the next 5 years) give a marginal boost to https sites, and the OBL from those sites. It makes large-scale networks more complicated and expensive to build and renew but this has been the game since 2008 and in my opinion, the reason why there are so few majoy players at the high end of network ownership (pharma/porn/casino)
So....
If it is a single site, your money site, fuck it why not go for it, its a few $
If its buying links, whatever, diversity is always good
If you own the network? You know what to do.