Kartik Yes there is a big chance you will get the same unique equipment in shop like the one you are equipped with. In my experience in the shop, I got four (4) lightning swords and a lot of lightning armors and accessories while wearing Lightning set in the shop always. Those 4 lightning swords are all used in combine method to find missing unique swords like Dark and Inferno so in total, 5 L.ning swords is what I got overall. Like those swords, the armors are combined as well.
The reason is because it is only my completed unique set in a long time. And I'm equipped with it even when drawing in the shop. For now I'm wearing Dark items when drawing in the shop but I only got lots of Dark armor and NO Dark sword. Sometimes I just laughed it off even thou I'm pissed 😅