It's really not easy for me to compute how many times each of my canvas bags has been used. But it's probably about 200 on average, since I've been doing this for over a decade and I've only had one canvas bag fail to death.
I'd bet 1000 uses is within the realm of possibility, but you'll probably need to do some repairs along the way.
Oh, I wasn't thinking about canvas bags. What I was thinking about, and what the law is about, is the thick plastic bags I've seen at e.g. Safeway checkout that they charge 10 cents for.
Buying these thick plastic bags seems to be what the checkout line guides people to do. Buying a canvas bag would require extra effort. People generally take the path of least resistance.
I'd bet 1000 uses is within the realm of possibility, but you'll probably need to do some repairs along the way.