nfa: the purpose of a power supply is to give your amplifier stage "clean" power. By this, I mean DC voltage with very little AC ripple, and very little voltage drop under peak power demand.

It doesn't matter how the amplifier gets this "clean" power, whether it is from a switching supply or a conventional supply.

One thing to note, the cheaper switching supplies tend to be "noisy."

I haven't seen many cost comparisons between switching supplies and conventional supplies, but the good switching supplies tend to cost as much as the conventional supplies. The big savings is in size and weight. Maybe someone else can comment on the cost trades.

Hope this helps a little.