How do you all value expired domains?

I'm not sure if this is the right section to post this question, but I'm wondering how do you value an expired domain. (That some registrar owns and selling it as a premium domain)

Do you base it based on how many domains linking to it?
Do you value it based on the popularity of the domains linking to it?

What formula's do you use to come up with a value?

First check the Domain Spam Level at Moz. Check Black lists on various sources.
Analyze the Brand Popularity.
Domain Authority
Trust Flow
Back Links
Analyze the performed Keywords

That is it from my side.

I do this:

Check for TF, CF, links and root links with Majestic.
Make sure domains don't have spammy links like those with Asian anchors, etc ...

Oh and I make sure that domains are indexed in Google ... if they are not, chances are it's penalised and ex-owner let it expire.

Wrong and then some wrong and all in all, wrong.

- Checking CF - What's the point? You can see the links pointing to a domain, you can check them one by one, why even paying attention to CF? I can't remember the last time I even checked that metric, it's completely pointless.
- Domains not indexed in Google - Bullcrap. They should be indexed in Google only if you are buying from auctions. If you are trying to find expired domains, then 95% of them won't be indexed. That's why you are checking it's history. To see if it's not penalized and whether or not it will get indexed.
- Analyze the brand popularity - What the fok? Seriously?

Christ.

Check the metrics. Check Trust Flow, check DA, check referring domains, check anchors, check the OBL of the backlinks and trust flow of the backlinks, check anchors, check history via archive.org, via domain tools, check hosting history and then make a conclusion. Registrars are selling domains at premium purely because of their names, not because of their SEO value.