I've so far used only cheaper buds when I'm out and about, but planning to get either an E-Q7 (but no removable cable!) or IE8; here's my take on the matter:
1) Spare some $50 or so on cheaper IEMs for public transport - meaning the riskier ones like buses and trains around town. You have a much higher chance of being mugged in a 30min ride through downtown (either on the bus, or somewhere on the street when you get off either the bus or the train) than you would in a long-haul train or airplane or cruise ship. These will double up as back up to the $200++ pair in case they're damaged, too.
As for pickpockets, a fellow here in my city and local forum had his Mustang and S9 in a bag. At one point he put his TF10s back on (I think they've been hanging on his shoulders) only to find the S9 and Mustang gone. So a cheap, easy to drive IEM that has no nasty habits like sharp treble or loud flabby bass out of a(n affordable) portable player (like a Clip) is a must.
2) Regarding damage to your expensive pair, it pays to get those with removable cables. No need for warranty replacements with a LOT of downtime, or if you still like them after the warranty expires, then you can just buy a cable. Heck, you might even get warranty for the cable, but still keep a spare set. Others get "upgrade" cables but personally if there's nothing wrong with the fit and noise on the stock cable, and they can be ordered cheap, stick with those. If some upgrade cables aren't that much more expensive, and no reviews complain of fit issues (too soft or too stiff that they don't help anchor the IEM, etc), then getting one isn't prohibitive, which is great in case they actually help the sound. In the end remember that, cable benefits debate aside, an IEM cable has a lot of other tasks than just hanging down from a cup/speaker binding post and just getting the signal from the source/amp to the drivers; they play a crucial role in how you enjoy the IEMs. If they're too bulky or too stiff, or too soft and has no cable slider, or transmits too much noise when you're moving (forgot what it's called but it's when you touch/slap/stroke the cable you hear an unpleasant sound)
