Chun Kee Stationery @ Lock Road, Tsim Tsa Chui
Chun Kee sells stationery supplies as well as fountain pens and inks. Like old skool retail shops in Malaysia, Chun Kee has a policy of giving hefty discounts on its pens' marked up prices. Sometimes it's possible to get fountain pens at good prices if you haggle like you are in a Pasar Malam (Malay for night market). Remember to ask for a further discount after the shop's discounted price.
For example, I was offered 30% off the price of a Platinum Curidas fountain pen I enquired about. I think the price might be lower if I stayed to haggle. Service is very friendly. The staff offered to show me some $$$ Namiki Maki-e fountain pens after I expressed interest in a similar but much cheaper Platinum gold foil pen.
But Chun Kee also sells affordable fountain pens. I once picked up a limited edition “Taiwan Flag” demonstrator by TWSBI, a Taiwanese brand, at below the market price after getting a discount.