At this point, I think whether you do such section/subsection verification is up to you.
I agree that it's certainly "cheap" enough.
Let me give you a point of comparison: One of the sites I work on uses MySQL. For some of the pages we display, we have to make as many as perhaps TEN separate queries into as many as THREE DIFFEERENT databases (all on the same MySQL server, though), including some that do cross-database joins.
That site, *ON AVERAGE* serves up one web page every 1.8 seconds. And we aren't at capacity, at all. (I think we wil be, soon, when we open up another two sites doing roughly the same stuff, so we may go to two separate servers then.)
If you do the math, that is well over 300,000 pages served up per week.
How long do you think it will take for you to get to that volume?
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.