Upgrade amp. or speakers first?

We have two schools of thought talking here. But both are in agreement that it is the amp/speakers match that counts.
I would audition many different combinations, find the most satisfactory and then begin the upgrade in any order depending on price, mood, dealer's attitude etc. Or would wait and get both at the same time.
Personally I tilt a little towards "speaker school" and tend to think of speakers (and the room)as musical instruments. After all I have Michael Green free resonance speakers - not the last word in resolution and many other aspects of sound reproduction but they play in a very natural way with any amplification I tried.