Dear Paul,
I'm slightly confused here - I assumed (it would appear incorrectly) that the SE were mapped in whole tones, and the standard and full libraries were mapped chromatically. So upgrading from SE->standard meant that you were paying for chromatic sampling (since, as you say, the articulations are fairly similar) and upgrading from standard->full meant you paid for additional articulations. If going from SE->standard doesn't include a) going from whole tone to chromatic or b) a significant number of new articulations, then why would anyone want to pay for it unless there are other benefits*?
* As you might be able to tell, I have recently upgraded from SE to standard libraries for appasionata strings, orchestral strings and a few horn libraries. I am perfectly happy with all of these, so only ask in a spirit of curiosity and with a view as to whether to upgrade to standard brass libraries (from their equivalent SE versions) during your current sale.
regards
Alan