I do not have this note in my collection and I do not believe there is anything special about your notes, apart from that these are from the first UAE series and is a very beautifully designed note (reverse side). First series of banknotes are always a favourite among collectors, me included, but I can't say why someone would pay you more than what you have expected. There is no shortage in supply for this note in such conditions, albeit various pricing. You have not mentioned the amount you have sold for, so it's hard to tell if your notes were sold well above the expected value.
The important thing is that you are happy with the sale.
The other alternative is to ask the buyer why? The downside is that if there was anything special about these notes, then you will be kicking yourself over this weekend.
I cannot read Arabic, and therefore I cannot tell if one of the notes is first or last or a replacement prefix. I can see one note has the serial number ending with 5555, but then this is either solid or half solid or any special.
Remember that there are always weird people that would buy at whatever it costs, me included
This is just my opinion. As usual, I could be wrong on this.
