What can I buy with HK$157.20

You can buy one of the following:

Henry Computer Vac
Retro toys for £12 (HK$142.90) from hawkin
Remote Control Can Racer
Toys for £12 (HK$142.90) from hawkin
Carl Sagan's Cosmos DVD
Inspirational and wide-appeal science series. Thirteen episodes, each one hour long. for £11.71 (HK$139.40) from source
Little Toy Maker Pirate Ship
Toys for £12 (HK$142.90) from hawkin
Vampirefreaks BDSM Against The Machines T-Shirt
Clothing for US$19.99 (HK$155.20) from vampirefreaks