Monster is unloved around here for their advertising hype, high prices, and their overly aggressive legal practices (e.g., suing a mini-golf course because they had the word "Monster" in their name). You'll find few people with extensive experience with Monster products answering you, I bet. I avoid 'em myself.
If you're willing to spend that kind of dough on quality in-ear phones, awesome. And, I hate to say it, Monster in-ear phones apparently are pretty good (I've never used them, but reviews seem to be good). But in the $250ish range I would go for a more established headphone manufacturer like Shure or Etymotic which are very highly regarded for their in-ear phones.