Usually, but it's even cheaper with a Armed Forces ID card
For cheap military boots, you could do worse than Silverman, there are also military specialists in Europe who are pretty reasonable as well.
There's actually pretty good reason why most of the boots you've been finding are so expensive: they're the ones that last a long while and don't require that much breaking in. The ones on the cheaper end of the spectrum (the ones we get issued) have a tendency to rip your feet and ankles to shreds - unfortunately the one method to help sort this out is actually quite disgusting and involves drinking a LOT of water. However, you'll have no problems after then.
I would recommend One Legged Jockey, but the boots they tend to sell are, well, crap to be honest and definitely not worth shelling out anything for.