Sauron is not really a higher order being than Gandalf and Saruman. I was reading somewhere the other day that the Istari were actually diminished by taking on their mortal forms as their true power would have made elves and men fearful of them as well. Sauron was undoubtedly more powerful as his height than they were at their height, but that is not an order level difference.
Off the top of my head, I recall that Sauron took on a large chunk of Melkor/Morgoth's power, which put him on a different level from the Istari and other Maiar.
Also, wasn't Galadriel born in Valinor, before the creation of the Silmarils? From what I understand, she was pretty much the wisest and (with possible exception of Sauron) most powerful being in Middle Earth.
(And so much for Tolkien being a mysogynist: apart from Galadriel, the next most important female character defies society's rules, rides to war in disguise and then faces off against the most powerful of the Nazgul. I think Tolkien portrayed female characters not as inferior, but in a way he thought was realistic for a semi-medieval society.)