I think this will be covered in the upcoming Lairs and Encounters and I feel like a kindergardener doing a potty dance waiting. My players just defeated a lair of carnivorous apes (4+1 HD creatures, re-skinned from Advanced Labyrinth Lord) and slept one and Charmed another. They are currently toying with the idea of keeping the two and training them. Would anyone be able to give me general advice on training times, cost and difficulties for such creatures in advance so I can answer these questions for them?
Short answer: Adults? If they can get someone with the right proficiency, 6 months to tame. (the Charmed one is already tame, but lord help ya if it wears off) They have to be tamed before they can be trained. 2 months for the first trick after that, then 1 month for each subsequent trick.
That's from White Apes, which are 4HD, and are probably close enough.
Carnivorous apes, if they're man-sized, cost 2GP/week to supply (man-sized are 0.5gp, carnivorous are times 4 in cost) and for a wild animal the trainer cost is 75gp/mo, so total 83gp/mo for probably a little over a year depending on what they're being trained for.