Cushioning insole only?

There is a brand of boots that has fit my foot very well over the years but, similar to your situation, never seemed to have an adequate amount of cushion. I have replaced the footbed in these boots with those from other shoes that I have quit wearing before they have lost their useful walking life. This method has taken what is already a good boot and made it better without the outlay of what, in my opinion is an outrageous sum for some of these inserts.

I used a Spenco foam insert found at a local drug store to my low cuts (Montrail Vitesse) and they worked fine. I have since moved on to Merrell's and Superfeet. Like orthodics, superfeet is not supposed to add cushioning, but rather arch support and to level out your foot, so that it is square to the ground.