It seems like a silly question to ask. One of the things that has made this country's armed forces the best in the world is the cutting edge technology in the equipment to which it has access. That may unfortunately be changing. The Air Force has been flying F-15s for 35+ years now. It is a very old plane which doesn't do well against modern competition: http://www.opinionjournal.com/editorial/feature.html?id=110011043. There is a much more advanced plane available, the Raptor, which completely outclasses every other plane out there. The cost is high, though as the link above demonstrates, the cost goes down with each and every plane that is purchased.
To me, it seems like this is an investment well worth making. We can't pretend to have the best armed forces if our soldiers, be they Army, Navy or Air Force, don't have the best equipment.