Compost Bin for apartment:  Hings Hong Kong 300HKD 180 Prince Edward Road. West, Mongkok 2308 1112, make sure to buy the bran (to accelerate the decomposition) HKD 100/ 2 packs.
Soil: Greenworld organic, 35 L, about 120HKD, Brighten Flower Market, 28 Flower Market Road, Mongkok. 2381-5330
Seeds: Graines de Fleurs between 20-25HKD/pack, Brighten Flower Market
If you are well organized, Julien orders its seeds twice a year, contact him to order some for you. It will save a lot on packaging and cost
Pots: Ikea