What can I buy with ₩17,990

You can buy one of the following:

Rock of crack cocaine
Crack cocaine rock, 0.15 gram for £10 (₩17,280) from drugscope
The Big Bubble Book
Toys for £8.99 (₩15,530) from hawkin
Mystery Ufo
Gifts for £10 (₩17,280) from hawkin
Nightmare Before Christmas Figure - Mayor & Light
Toy for US$14.99 (₩16,890) from vampirefreaks
Build Your Own Camper Van
Retro toys for £9 (₩15,550) from hawkin