Surely if you purchase a domain (domain1.com) and redirect it to your existing domain (domain2.com) you expect to loose all ranking for domain1.com. If 301's are used then the objective is simply to pass on authority, not dominate the search results with 2 domains. If you want to keep domain2.com in the index then you would take Rebecca's option 2 or 3.
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.
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”.