Sony could possibly not accept any of those products for use online, given they would still allow use on the product for single user use and wifi i think. They could maintain a decent share of the value they have in retail.
Especially given the expense needed to gain benefits from online use, that is access and allowed elsewhere, given the extended time taken to use services online with increased expenses and gains from using services online. Given that playing online for use of most media, having online play is useful, but given that socially speakinng seems to rule more of the use of online, that buying the just good games and not having much of an online connection would be better off to do then, taking advantage of online features.
Given they shouldnt lose much value due to the lack of online uses. Given lie mst places due to these natures online use is needed to use such things, but in response value has been lost not say a monetary means given the prices have gone up due to lack of use, no reason to lose any value to say, but lack of user friendly uses. Rather its 5 dollars or 500dollars if someone cant really use for what it is for or could be used for without additional needs, its worthless.
Given though a stolen PS3 might find better value at a lesser price then one at regular retail price. Just going through more stolen avenues creates more additional needs then to say retail. And retail is going to charge and tax like none other. And when they arent then stolen avenues will, the biggest problem is lack of decent "rights" or understanding of product to consumers.