there are 2 kinds of expired domains. one is the kind that you buy at an auction, and the age doesn't reset. the other kind is the ones that have completely expired and been removed from the icann registry. this is the kind that is available to buy immediately at any domain registrar for around $10. is it a good idea to buy this kind of expired domain for a PBN, if all the metrics are good, backlinks are good? or if a domain is dropped, the backlinks become worthless?