Kapla Blocks questions

[Good Morning Dewdrop]

I think DD would love the Kapla Blocks (same sized plank type building 'blocks'). Questions are

- how many is a good number to have? DD is 10 so should be able to build some complex things

- does every set come with building ideas with pictures or do I need to purchase a separate booklet?

- any idea where to get them the cheapest - I know they're not cheap to start with!

Thanks!!