Reduce reuse Recycle:watering cans from plastic milk containers

Having bitten the bullet and planted some seeds my kids are getting interested in gardening again!  One source of tension though is the lack of kid sized watering cans.  What is so radically different about kid sized (proper) watering cans that makes them twice the price?

So, to save my sanity I was going to buy 3 more normal watering cans (at about a tenner each!).  Then I found this pin on Pinterest.  Now I have as many watering cans as I want all for free.