Essrand,
I bought my Frankensteins a little over a year ago and used Pangea AC-9 power cords for awhile. They work well. I have not compared them to other cables costing under $100. However, they are comparable to my more expensive JPS AC+ power cables. The difference is subtle, with the Pangea perhaps being just slightly darker and less transparent sounding, and the JPS cables perhaps offering a little more clarity in the bass notes and more high end sparkle. It is hard to tell. There is a 1.5 meter pair of the AC-9's on eBay right now for $79.99 each. The Signal cables seem like a very good deal, and they would have been something I would have tried if I knew about them.
I have had a Synergistic Research graphene power cable for 6 weeks now, and just ordered a pair for the Franks. The improvement when I put the graphene cord in my dac, and later my preamp, is noticeable in a good way, and worth the relatively modest investment (compared to the price of other high end cords). I will post my impressions of how they work with the Franks in the SR power cord thread. The graphene cables from Cerious are reasonably priced, IMO, and worth consideration. The ones from SR are not that much more in price, plus with SR you get a free premium fuse with the purchase.
Tom