You might try the current auctions here on AudiogoN for the Electraglide S.O.T.U. power cords. These are Electraglides top power cord available in a no reserve auction. You might be able to win one of these auctions for under $350. For that money these cables would probably be hard to beat. They retail for $2700. I haven't tried them personally but I have heard other Electraglide cables and thought they were very good.
Another option would be used Shunyata research Taipan Helix power cords which sell for the upper end of your price range and are exceptional.
Another option would be used Shunyata research Taipan Helix power cords which sell for the upper end of your price range and are exceptional.