What Is Special About These Two Uae 10 Dirham Banknotes ?

Yes, I am putting it down to a lucky day. When researching the notes prior to listing I didn't find anything unusual so the final price was a real surprise and I wondered what I had missed. However I think it was probably just a case of a personal desire from 2/3 bidders, for whatever reason, and a good day for me !

Google can't answer questions like that. (I'm not sure we can help either).

To take a stab at the mystery, I would suspect it has something to do with these examples being from the first series of UAE notes (& a good time to list- as you suggested). Any denomination above 1 are usually much harder to source in higher grades so the prices go up dramatically. Looking on ebay I saw a PMG UNC65 UAE P-3 example list for $700USD (& I can't find it now- so perhaps it sold?)

There are several copies/reproductions listed (unfortunately- but a good sign that the note is in demand). Many collectors have no idea how to grade & just want one VG-F example. It may be that some media coverage was released re: the UAE first series (or the Umm al Qaiwan capital city on the reverse) or some fact we're missing. As you suggested, you probably got lucky that your listing had more than 1 bidder & they likely got into a bidding contest.

Anyway, good to hear you did well (at the end of the day).