I remember reading something similar but I can't find where; so thought I'd post it up here. If you buy an old site. Let's say something expired or abandoned. Or bought from flippa.com or sedo.com or any other auction/domain seller. Does the PR come with it? Additional: Will crawlers still check back often as the old site? Thus, reupdating and indexing with the new owner's new material? Thanks
Some do, some don't. Use a page rank checker to check the pr of the domain or website in question before you buy it. Usually the pr fades though after it is not associated with the old website, unless you keep the backings coming in regularly.
It depends on a lot of factors - if it's been ages since the site has been expired or dropped then the impact will be more limited than if it's only been down for days or weeks. You can check on archive.org to see when the domain last had content, and what that content was about. It's not going to replace your own SEO efforts - and you won't get all of the credit that the original site had - but it can help you kick start the site. Just make sure that the previous site wasn't about something dodgy - porn, gambling, spam - that will make it harder for your new site to rank, not easier.
When a domain is dropped, Google refreshes it and it restarts as PR0. However, those backlinks will most likely have stayed, if it has only been a short period of time, so you should be able to regain it, or at least a rank below.