I liked the Fusion Audio Enchanter with the X150.5, which I bought used. The price for a new cord is quite high and above your budget, but you may be able to find one used. Another good cord closer to your lowest price point is the Audio Arts Classic, which is very good for the money. In the past, I would have also recommended Mojo Audio Enigma power cords, but prices have gone up in recent years and they seem to work better for me on source components than on amps.
