Problem is, it's a point that can be argued, because it's right there on the page you just cited. And specializations ARE given a lower cost, on that page.
The sample characters use the first example, where specializations count as a full skill level, but the chart on p. 97 directly contradicts this -- it doesn't specify that specializations bought with free skill points count as one of these levels.
There's also the contradiction between the two pages; p. 87 has the "(or 2BP)", while p. 97 says 1. So the question still remains: do Knowledge skill specializations cost 1 Build Point, or 2? If it's the former, then the "two specializations" idea you mentioned would be a perfectly valid argument. If it's the latter, than the summary page needs a touch of errata.