I look at things in black and white. Good or bad, right or wrong, you either have the part or not. I get very pissed when someone will list a product, you order it only to find out it's B/O'ed. If it's not available say so. Companies that jerk customers around eventually suffer the consequences.
I just placed an order with Grizzly Industrial. One of the items went on B/O but they emailed me letting me know and asked if I want to accept the B/O or cancel the item. To me, that is an acceptable practice. Just don't let me hang!
If the company your dealing with is a sole manufacturer and you want their product, your pretty much stuck with their terms. If not and they jerk me around, I go somewhere else. Even if it cost me a little more. JMO