A $500 DSLR isn't an expensive camera and won't attract undue attention. I routinely carry around my $2,000 DSLR with an additional $1,000 or so in lenses, and used to carry a $2,000 video camera (though I've switched to an HD camera that was only around $800 or so). I never had the slightest problem. Obviously, don't put your camera down and walk away. Otherwise, you won't have any problems.