Mike Teezie said:
I think the answer depends on the subject and it is not unreasonable to own several heads. Some heads are not expensive. I paid less then $30 for my Bogen "delux 3D" head and it is the best one for feil macro photography
If you need to track a moving subject, like wildlife or sports then a ball head is best by far because it is quicker to use. But if the subject either does not move or moves at your direction (a model) then the three axis head is best because it is easier to make fine adjustments.
If you can only get one get the three axis type. A very good three axis head is not expensive ($50 or less) but a fair to decent ball head would cost 5X more. Also a cheap ball head is really horible. To be usful the ball must be large and very finely machined. The ball head should previde an adjustable amount of friction with no spots that skip or bind this requires precission metal work which is not cheap. You will not really need a ball head untill you have a fairly powerfull lens and need to track a moving subject.