hi again,
also note that many cv inputs are "adjusted" for 1 volt per octave. so, instead of using a dac over the complete range, you might do a combination of a dac and a switchable gain&shift stage. say, the dac handles 2 octaves, and you have 5 different octave-base selections available.
pro: allows for much finer tuning of the note con: requires more control software and a bit more electronics
a rough guess would be around 8 or 10 bucks per 16 bits / 5 selections. for simplicity i would recommend to use 4 selection with 2 1/2 octaves each, because analog 4-channel switches as chips are readily (and cheaply) available.
greets,
chris