Ten times better?
I owned a pair of IE8s and IE7s, and sold them both. Found the IE8s not worth the price due to the lack of iso and at the time, I favored the Westone 3 sound sig (just more excitement in listening to me). As for the IE7s, I tried them too, just for kicks, and sold them pretty quick. I also felt they were overpriced for what they were, but decent. I now own the Trips (one pair stock and one reshelled on the way from Fla.), and never really feel the treble is too bright nor the phones fatiguing. I use Sony hybrid tips with the TF10s, which to me really brings their sound home. Tips/fit play such a major role with all these phones.
As far as honoring warranties, Amazon will give you its 30-day money back, but if your IE7s fail six months from now, that $169 price tag is going to seem irrelevant after Senn says tough luck. Amazon is not going to replace/fix them 6 months later. I guess the question is are you willing to risk the price difference and hope they don't fail within two years (is that the Senn warranty? Just guessing). I've done both, but just something to ponder if you get them from ZElectria & Sarjo Wholesale, Amazon or no Amazon.