I don't see why you have a problem then. If you think the spies will be spotted and taken care of so quickly then ammo won't even be an issue. I guess I don't get your position.
Really though, even if an engineer is right on top of his stuff you can sap without them spotting you. It just takes a bit of awareness of the situation. For starters doing it when nothing is going on is just asking for death. As is doing it in plain site of folks, a little patience can go a long way to causing max damage.
Something a lot of spies don't seem to know is that sapped structures don't work. So its very effective to sap a dispenser and when the engineer goes to repair it sap the sentry and backstab the guy. Then cloak, re-disguise, and finish the sapping job.
I honestly have very little time on the spy and yet usually I'm very effective when I switch over to play the class. I shutter to think what a dedicated spy can do.
PS - I haven't decided if the morons who backstab you in the midst of a cluster of you, your teammates, and your team's sentries are just downright amusing or completely annoying, but they do seem to home in on me quite often =P
PPS - Anyone have the defend Gravel Pit without giving up a capture achievement? That one seems like a real pain in the ass.








