I'm not sure what a Low Deck is, or a piezosummer (piezo buzzer?), but the additional parts don't seem to add enough value to bring the price to $66. Assuming that that value is in US dollars.
Sparkfun sells the Arduino by itself for $29.95:
They have a starter kit for $59.95 that includes more stuff:
But, it depends on where you live and where that kit is being shipped from. It may be a good deal if shipping is cheap (and fast).