This is the most common question I get, and want to try to answer it. The easiest way to put it is that there many pads and lots of moving parts on a woodwind instrument.  Just about all of them at one point or another need attention.  I always look at an instrument and try to find the most glaring problems such as torn pads, cracks, loose posts, pads that aren’t touching all the way around, and fix those first.  In many cases, such as with professional clarinets and oboes, I remove all the keys and stop them up with small rubber stoppers then put it on the mag machine to see if it has suction. Then I begin adding one pad at a time checking that each one is sealing perfectly. This takes a very long time, but it well worth it when you hear the instrument and it is resonating to its full potential. A usual oboe repad is $850, this is because it takes about 12 hours to do it correctly.  

So the answer really is, it depends. .