Follow Sean's advice, you just have to search for them.
Last year I bought a new/old stock of 9.4V 700mA chargers,
good for CV or CC application (leds) less than 2€ each.
I'm using them for everything, once learned the circuit
inside it's easy to mod the feedback circuitry to change
the output voltage/current (by a reasonable amount).
Now I simply take the calibre, and open an hole in the plastic
case, in the point where I know I will expose the resistors
that set current and voltage setpoints.
Another alternative is use plain old transformers, check
your power requirements, the low power ones are pretty
small and low cost. Two relays and a micro, a 3VA one
could be enough.
Fabio.