Ideas for 8 year old and 11 year old boys

[stripes1]

Can any one help with ideas for two godsons. My DS is only 3 so I'm a bit stuck for older ideas. I normally spend £10-£15. Thank you!

My eldest is 10 and has asked for transformers, horrible histories books/DVD, horrible science experiment kits, addictaball and 3D puzzles. All of these cost around the £15 mark if you shop around a little.

Thanks, think I might get the 11 year old the addictaball, looks good fun!