It's ranking high today! What could be the problem? NO. JUST STOP. Unless you know the entire history of a domain, you may be setting yourself up for failure before you begin. SEOs (and business owners) use a variety of tactics to get a site ranking high in search results. For some of these methods, we'll just call them "questionable". These methods could include everything from buying links, overuse of directory submissions (non-industry related), duplicate listings, poor quality backlinks, and guest blog comments.
Yes, buying existing domain names can be profitable too. Existing domains with a potential for profit can be found using Sedo. Make sure you pick domain names that have good traffic, backlinks and Google PageRank under 17 characters. Also, steer clear of existing domain names containing special characters or numbers because they are not likely to be sold.
I have an interesting twist on how I have done it in the past. I will buy a domain and use it as a development domain for blog posts and things of that nature. Then over time it will gain DA and PR. Then I will sell it off and buy another development domain and start the process over. Not quite the process you mentioned, but it works. People will link to the development site to show things off as well  sometimes, so that helps.
Finally, we’ll look at a bit of a different animal in the expired domains world and that’s pending delete. To do that just click on the pending delete button which is right next to the Go Daddy Auction’s button. What this does is it shows you domains that aren’t quite deleted yet. So, they’re right before they get into this deleted category in expired domains. They’re going to be deleted, so they haven’t been renewed by whoever registered them, so they’re going to get dropped.
Check DA/PA: The “Domain Authority” and “Page Authority” metrics gained significant popularity over the last few years. They seem to correlate well with a domain’s ability to rank in the search engines and hence, a domain having a high DA/PA will typically have a higher value. This is not to say domains with low DA/PA can’t sell for a lot of money because, at the end of the day, it’s just one factor. However, it’s good to take a look at these as they may tip the scale in favor of or against some buying decisions.
For the following TLDs you can now find a expired/deleted domain list. .gi, .gl, .gy, .hn, .ht, .ky, .mu, .om, .pf, .qa, .rw, .sb, .sm, .sn, .st, .sx, .tc, .tl, .ug, .uy They also show up in the Deleted Domains (last 7 days) list and in the Domain Name Search, however they are not in the pending delete list! I do not have a working droplist for them yet, so that is why they are not released in the pending delete list yet.
That being said, many things have changed over the years. The days of MFA and quick flips are mostly gone. My advice to those new to domaining and wanting to give it a try is to take it slow, do your research, and if you do purchase a domain with the hope of turning a healthy profit - put some real time into it and build something useful. That way it's easier to monetize and easier to sell.
They see a domain’s price tag and they can instantly tell whether it’s under or overvalued. This is probably the most important skill one should have in this industry. Neil Patel has an interesting related quote: “The most important thing to remember when buying sites is that you always make money on the buy, never the sell.” In order to successfully do this, you must be able to spot undervalued domains. This is what will ultimately translate for you into a handsome profit margin when you get the opportunity to resell the domain for its “real value”.