Here I thought you were going to ask about going through security with your shoes on.

There's nothing in bike shoes that would alarm security - even if they did have a steel shank (which they don't), it really wouldn't resemble a knife, and even if it did, they'd just look at the shoes to verify it wasn't a knife. BFD. I've done it twice and they never batted an eye. Large DSLR cameras and the like are the most likely to get a second look, but even that is just five minutes out of your time.

I think carrying your shoes on is a good idea. It's not about the expense for me (really, I doubt that your BIKE was less expensive than your shoes, and it's obviously traveling by air somehow; and the entirety of clothing in your suitcase, even if it isn't expensive clothing, would have a hard time costing less than even the most expensive shoes. Trust me, I've had to replace three days' wardrobe TWICE when my luggage was simply delayed, so no insurance reimbursement either ). It's about being able to replace my shoes on short notice at my destination. If they lost my pedals, well, okay, Look Keos are pretty easy to find. If they lost my shoes, who knows whether a LBS would have a shoe that fit me, and even if I did, I'd have to go through setting up the cleats.

That sort of thing is the same consideration I give when deciding to check or carry on anything, really. Not what it would cost to replace it - just have a good list so that you can put in an insurance claim if they do lose or damage something valuable. But, how much hassle it would be to replace it, and whether my entire trip would be for naught if I couldn't.