But nowadays, there's plenty of product that does exactly what we want without having to be a power supply expert
Someone mentioned Astrodyne as a supplier of switching supplies, I use Power Trends (TI) and they are dirt cheap and work well.
We have a series of units operating off a National chip in a curcuit designed here. These units have a 5%/year failure rate though being well within spec. The "ready made" PT modules do not fail and the difference in price is peanuts.
I know no engineer that can not design a switcher, I know no engineer that can make one as good as the "specialists".

Erik