In need of durable ear buds $50 or less...

The ultimate ears metro.fi could be a good choice. Many places online sell them for about fifty dollars.

imo, one of the pros of having the shorter wire and extension cable is that if it gets caught on something, it usually just pulls them apart instead of tearing the connections in a single wire earphone. Just yesterday I got mine caught twice and both times the plugs were pulled apart, but no damage was done. Wow. I usually have bad luck with earphones, but my mdr-ex71's have lasted me for six months already, and they're still going strong. They got a strong recommendation from me. :)

Agreed. The ex71s are also good for running because of the detachable cable. It allows me to use an armband and not have to worry about the cable flying everywhere.

I don't RUN with my iPod, but I do walk around the nearby area.
Somehow, my earbuds just get destroyed.
I was looking at those sonys, the cord actually turned me off at first, but now I get it's there for a reason.
Also, will the ear-inserts come off easily? That's been a problem for me in the past.

Edit: I notice several different 71 models.
there's SLA, SL, SL/WK...
Are they all the same?
And there seems to be several reports of "rapid cable rot" which doesn't sound very durable at all.
Of course, this is on amazon...

The ex71s are meant to be worn around the back of your neck, that's why they have the J-cable instead of the symmetrical Y-cable.

Not to sound gross, but from a sweat very easily when I exercise, even if walking. The cable is still in perfect condition.

Don't know about the differences between the models.

If you don't mind the shorter cable, you could just use that part when running to reduce the wire length and therefore reduce the "internal" sounds you make when the wire bounces against you. Or if you have an armband close enough to your head that you can just attach the short cable to it and go.

I don't run with my iPod, but if I did, I probably wouldn't use my mdr-ex71's because I hate said sounds when the wire hits my chest or arm while moving, so I personally would just use earbuds that sit outside the canal to avoid that problem. But if it doesn't bother you, then by all means, use them.