You are in the same boat I was in needing long 15' runs. The first decent cable I bought was Kimber 4TC. Kimber 4 & 8TC may not have a big glamour aura in the world of audio nervosa, but there is a reason they are consistently mentioned over & over as a good choice. The 4TC is a very decent cable with no aural sins of overt commision. I then wanted something better and bought the Analysis Plus Oval 9's. Yep, that was better, noticeably more detail, airiness, ambience, etc. Then I tried biwiring the 4TC and Oval 9. Better still, but not by the margin that the Oval 9 improved over the 4TC. I'd originally thought I'd sell the Kimber to pay for the Oval 9's, but I ended up keeping both and wound up with $1000 worth of wire driving $1700 speakers. I guess the point of all this is that your Maggies are very revealing of anything downstream. I'd suggest buying used to maximize bang for the buck. The Goertz cable mentioned is a favorite product line of many Maggie users. Kimber and Analysis Plus sound great, and I'm sure there are choices that you can pick up from Discovery, Music Metre, and others that are neutral, easy to live with choices that will do a good job. At your price point though, I think you'll do better to get a quality single wire and use a short length of quality cable as a jumper. The one exception I'm aware of might be the really good deals out there on closeouts of PS Audio's biwires. I've seen good PS Audio biwire cable in your length going for about $400.00. Good Luck.