Agreed... my first AC outlet upgrade was a free cryoed Pass and Seymour (retail less than $20 I think) that I got with a VH Audio order. It sat in my junk drawer for six months before I got bored on a cold Saturday and tried out the voodoo. I was physically startled when my system came back on. Later I tried more expensive gold and copper Furutech outlets. They sounded different, but I preferred the sound of the cheaper P&S. Duster over at audioasylum has written extensively about the different tuning properties of the different receptacles he's tested against one another. The Oyaide R1, however, is a different beast. Those guys seemed to have stumbled upon something with that incarnation.
I should probably just go and try it, but I'd be willing to bet you can easily tell the difference between your typical 50 cent outlet and a $20 hospital grade outlet with even a jambox, er, iPod dock or whatever.