As an expired domains seller myself, I can say a few BS arguments going on in both sites. Many of the replies are irrelevant to the question asked by the OP. Anybody who says expired domains do not work or PBNs do not work are just giving a BS. And metrics matter a lot though there are a lot more checks than just metrics. You need to check a lot of stuff including history, past penalty etc. which would come with experience.
If the domains is really a goldmine, $80 is not a bad price for TF CF DA 25+. The backlinks and quality has to be decent enough to demand the pricing though. If it was a spammy site, Chinese history, PBN history or any other major problems in the past, just let it go. It would be money wasted. But for good quality authentic domains with real/organic backlinks, natural anchor text ratio and possible backlinks from authority sites, it is well worth the price.
If you want to go for something lesser, you can go for TF CF DA 15+ etc. which would still be effective enough and go for a lower price.
One more thing. Try to diversify backlinks and not depend only on PBNs.
