$999K

Well this are the material for our playground:

Toothpicks- Got for free/ donated by our Mr Ching Yong
Corrugated Cardboard- $3
Styrofoam board- $1
net (spiderweb)- Donated by Ryan
TOtal- $4

If it is build in real life:

walls-3K
wood- 1K
net (spiderweb)- $100
cushion balls- $200

Total- $4 300