A nitpick but it's really important that HNers understand it: users do not, in fact, pay for bug free products. They pay for products which achieve the benefits promised to them, bugs and all. If they wanted to buy bug-free products, they'd a) make decisions about software adoption driven primarily by externally visible indicia of bug-freeness and b) pay prices similar to that paid by e.g. the Space Shuttle or flight control systems. Users do neither of these things for most software.
A nitpick but it's really important that HNers understand it: users do not, in fact, pay for bug free products. They pay for products which achieve the benefits promised to them, bugs and all. If they wanted to buy bug-free products, they'd a) make decisions about software adoption driven primarily by externally visible indicia of bug-freeness and b) pay prices similar to that paid by e.g. the Space Shuttle or flight control systems. Users do neither of these things for most software.