in our region, Arduino clone (Freeduino=Arduino Duemilanove) costs approx.$30 without cables etc. (
Freeduino 2009 – аналог Arduino Duemilanove)
In your shop, the same model - $17
servo motors :
http://arduino-direct.com/sunshop/index.php?l=product_detail&p=128 in your webshop $8.50
http://shop.roboforum.ru/product/servoprivod-sm-s4303r-plast-shesterni-postojannoe-vrashenie/ same model - $21 . almost 3 times more expensive :(((
so as you can see, it depends on region : in any way,I would order ready kits from your shop because it saves me lots of money.
shipping from China to Russia is quite low if not to use DHL.
The starter kits from yourduino already have very good pricing.
IF there were several basics video lessons on how to work with these kits, that would be perfect.
You have some great written tutorials http://arduino-info.wikispaces.com/BrickStarterSet
But modern kids are lazy to read, unfortunately ;(