Amazon has DeWalt TSTAK II 13" Stackable Flat Top Toolbox for $12.97. Shipping is free w/ Prime or on $35+.
Product Description from Amazon
- Flexible platform of the tool storage allows different combinations
- All units of the tool chest can stack on top of the other, connected with durable side latches
- Bi-material handle on top of each portable tool chest is designed for easy and comfortable lifting
- Heavy-duty metal latches for rust resistance