Use the "30-Day" rule on nonessential purchases.
I first heard about this in the mid-90's on christian financial expert, Larry Burkett's, radio show.
Any item you want to buy (we are talking a want, not a need) that costs over X amount of dollars, write down the item, the price and the date. Place this somewhere obvious, a magnet white-board on the refrigerator works well. After 30 days see if you still think the purchase is a good idea. In the mean time research the item. Look for a better price. Read reviews about the item. Would a cheaper, similar item work just as well. More than likely you will realize it was gonna be a stupid purchase.
You need to set a dollar amount and things you are going to wait to buy. Maybe anything over $20, $50, $100 etc...Decide what is best for your situation. X=$50 for me.
I am doing this right now with an iPod shuffle ($46 at Amazon). The only place I would use it would be while running, but I ran for years without music and I am fine with out it. 6 years ago the kids got me a Shuffle for Father's Day. Since then I have sweated to death 8 iPods and MP3 players. It seems I have toxic sweat. The latest one died a few weeks ago. It lasted 8 months, the longest out of any of the 8.
I am leaning towards not buying another one. I have plenty of other ways to listen to music: Slacker or Pandora on my laptop (or any computer with an internet connection), music stored on my phone, the home stereo, car radio etc...It's been nice running without music blasting in my ears. Just enjoying the run. And I ran for 30 years or so without music so I don't need to for motivation.