Two choices for you
Audio Technica ATH-CK10 - Pristine sound that most other IEMs are benchmarked against. Super durable, high quality cables that can be bunched up and shoved in a pocket without worry. They're in your price range. I love mine and have grown to like them better than the UE TripleFi 10's that I had briefly before one of the drivers died in it. (avoid the triplefi, they're not durable at all, loved the sound but they don't stand up to abuse).
I have owned them since October. I had a relative order a pair for me when I went to Japan for an inlaw's wedding. They're in the same condition as when I got them. Straight out of my iPhone they're very neutral. If you like that, great, if not you could use a portable amp to get the most out of them though, high impedence and all. I use a Fiio E5 with the line out cable, it's great with them, or an E3 works great as well. They also sound fantastic un-amped from my computer with a Sound Blaster X-Fi HD 5.1 USB.
Oh and get foam tips for them! Comply T-200 tips fit them perfectly and really round them out and help give the bass that definition they're known for.
Panasonic HJE900 - Casing is made from Zirconium. AKA Diamond. You can run over these with a car and they won't have a scratch on them. The cables are replaceable, tips are readily available from comply foam. I own these as well. My dog ate them once, chewed one of the earbuds off the cable and swallowed it. I made him throw it up later, cleaned it up, and it was no worse for the wear. They still work great. If that's not durability I don't know what is. They also sound great without an amp right out of my iPhone. Some say they're a little bit V-shaped (strong bass & treble, weak mid), but that can be fixed with an equalizer. They sound great out of the box though. They lack the clarity of the CK10s but don't need an amp and I dare you to find a more durable pair of IEMs. Detatchable cable and body made of zirconium. What more can you ask for?
The sad part is you could have bought the Panasonics for $80 about 6 months ago, but apparently they've discontinued them in the US like Audio Technica did with the CK10's, so you have to pay a premium to get them.