Merchandise at HKDL has definitely improved since my previous visits! There was heaps of awesome stuff! If you are into tsum tsums, you will be in heaven lol! Lots of tsum tsums and related merchandise. They also had heaps of cute hair accessories and jewellery. Lots of cool unique items in the Mystic Manor store, including some glow in the dark t-shirts and other items. Lots of nice t-shirts, pens, notebooks and knick-knacky stuff. Plus they often have special merchandise events - for our visit they were offering cute Mickey mini casserole pots as an extra purchase option at some of the restaurants. Lots of cute Duffy/Shellie-May/Gelatoni merch if you're into those characters. If you're into pins there are lots of nice ones available, and pin trading is common, so don't forget to take your traders (unlike me lol!). Our visit also coincided with the start of their springtime event, so there was heaps of special merchandise for that, mainly featuring characters in pastel Easter Egg designs and some of the rabbits and woodland creatures.
Most stores had specials tables that offered 50% off 2 or more items, or 75% off 4 or more items. Mostly the items were t-shirts and childrens clothing, but there were a few other items on some of the tables. There were also random 50% off specials scattered throughout the stores. If you have a magic access card you will get a discount off full priced items only. It's worth noting that there were also special freebie pins available to magic access members, which were available to collect in the Art of Animation building. I believe they have special offers like this for magic access members frequently. If you're thinking of getting a magic access pass, and not using it for a discount on your room, it could be worth buying a day pass and upgrading when you get there. They were offering some great incentives including meal vouchers and other freebies.
For the record, much of the special merchandise was also available at the
Disney Store at HK airport. If you have a magic access card, you can also use it for a merch discount there. I recommend buying stuff when you see it though, as there were a few exclusive items only available in select stores.