You are probably the first shopper who has said $400 to $700 is not all that expensive
Button cameras work with button down shirts. I was able to find some polo shirts with a placket deep enough to accommodate the button cam, but it wasn't easy and will depend on your body type. I wouldn't suggest stowing the DVR in a shirt pocket. Most of us put it in a pants pocket and you need to be sure the shirt is long enough to cover.
Equal rights for others does not mean fewer rights for you. It's not pie.
"I prefer someone who burns the flag and then wraps themselves up in the Constitution over someone who burns the Constitution and then wraps themselves up in the flag." -Molly Ivins
Never try to teach a pig to sing. It's a waste of your time and it really annoys the pig.