the podiatrist I worked with always (well, unless there was an obvious defect) had patients try cheap over-the-counter arch supports/insoles and physical therapy before he would send them to get custom orthotics.

And there are ways to customize plain ol' $5 Walmart insoles that can make them just as corrective as a custom $375 pair. (though they won't last as long, maybe a year or two instead of 10 years)