I think the only reason prices would ever go UP, would be if the cost of generating electricity went up.. In which case, your in-house computing would cost more, as well.
Short of that, the trend seems to be costs going DOWN. Amazon recently noted their 42nd price decrease.
Why would I ever pay for CDN service, now that GitHub Pages provides CDN service for free? Am I missing something? We can all use Fastly for free now...