the reason that "cheap" RAM is cheap is because it's usually returned stock that gets dumped in a zinc bath to float the chips off which then get resoldered back onto pcbs and are then sold as "new" (but budget) - it's effectively a form of commercial recycling. But that's the reason cheap RAM is usually rubbish. Been going on for years, I first came across this scam in the mid '90s when component prices started falling.
