there's a pricebreak @ 25, which might be a bit much ($87!). i think dorkbot pdx still does a group buy, but i don't know the specifics... also —› make sure you get the DIP package (unless you feel like surface mounting). each AD5206 has six channels, and generally an oscillator requires at least two channels (one for frequency, the other for amplitude). so, each one could effectively give you 3 voices.
if you got a pre-assembled unit or kit, then you'll have one of these already, but extras are always nice!