I've tried several cords and one of my favorites for subwoofers is Cardas Golden Reference. I use it on my Vandersteen 5A subwoofers and it sounds great. You can find them on Audiogon under your $400 for 1.5m.
Power cord for SVS PB12 Plus
I have a Signal Cable Magic power cord connected now and it sounds good but lately I have been thinking about upgrading. What would be a good match? I have been looking at Acoustic Zen and Shunyata but not sure what models will work for me. Would like to stay around $400 for 1.5m cable.