Where is she staying (which neighbourhood) and how much "effort" does she want to put in for you?

Quickslinger MAY be found in some of the specialty stores in Yai Ma Tei (or obtusively expensive at one store in Wan Chai Toy Street) but he isn't a common figure to find.

If she is going to Toys R Us, tell her to visit the one at Harbour City in Tsim Sha Tsui (It's a touristy area so she will probably end up there anyways unless she's a former local).

If you want some real cheapies and she is adventurous in terms of getting around, Wonderland (North Point or Whampoa) have a few figures still reduced to clear - YoTG Optimus, Generations Jetfire, Brainstorm, AoE Optimus + Trailer with Red Sideswipe come to mind... they also have a Chinese New Year 15 % off sale this week. They have MP Tracks for around HK$350, Road Rage about the same and slightly cheaper for red Bumblebee.
(I live right next to the North Point one so I visit it regularly. )

But it really depends what you want and where your mum is willing to travel and explore for you. If you can narrow it down to exactly what you are after and she doesn't mind hitting the toy malls I can probably suggest a couple of stores in Sino or In's Point but if she is a first time visitor to HK it might be a bit of a culture shock entering those places.

Quote Originally Posted by Handsprime View Post
My mum is going to hong Kong in a few weeks and she gave me a budget of $100. What good transformers could I get there that you can't normally find here or are cheaper there? Is quickslinger also available there?