If there's a Performance near you and you don't want to shell out for Sidis, Forte shoes tend to fit rather wide.
But seriously, you have to try them on. I use cheap, worn out Pearl Izumis for short commutes/errand running or when I'll be off the bike a lot, not on trails. For faster/longer riding and racing, I use some nicer, stiffer Shimano M160s.\
As others have said, the really nice Sidis have replaceable soles. That said, I'm as much of an environmentalist as anyone, but don't see it as a big deal to get a new set of cycling shoes every year or so. That's certainly longer than running shoes ever lasted me.