What about option #4 - Redirect your existing domain to the old domain? I bought an old domain that is 100% relevant to my current domain but currently has with very little content. It did have more content fours years ago. The old domain is 13 years old, pr=3, while my current is 7 months old pr=1 and a decent amount of content. The old domain I purchased was not expired though and I do not know if this makes a difference. What are the pros and cons of option #4? Am I correct to think that option #1 would result in no benefit from the old domain's age value and if so why is it not listed as a con, a MAJOR one. Its hard to believe that a 301 using option 1 would give my existing domain 13 years credit but I'll take it if it does.

We just need to take the Archive.org url and plug it into the Dom Recovery software and again, if you just hit recover, paste in the snapshot, click next, next, finish, and I’m going to let this one run in real time for you so you can see just how quick it is, and right now it is downloading the initial page, and now it’s downloading all of the other pages.

Of course, this does not happen equally across the board. Some site owners are lazy and barely put in any effort. As you can probably tell, the four situations I outlined above probably will not occur for website owners who are lazy. Now, for website owners who put in the work and the time for their online properties, you can bet that they would get to benefit from the four situations outlined above.
The bottom line is, drop domains deliver traffic. How come? When people register a drop domain and build a website on that domain, they often attract backlinks. They also can update their website and generate a community or a brand. Whatever the case is, there are four things that happen that results in traffic for those websites. They create a backlink footprint, which drives direct traffic. This backlink footprint also produces SEO benefits. The more these website owners promote their website, the more goodwill they build up in their target niches and online communities. Finally, the more they manage their online blog, website or information site, they gain some sort of presence on social media.
As you can see just within expired domains they have over two million deleted .com domains. Now, this is obviously overwhelming if you’re trying to look for domains. So, you should use a few filters to make the search process a lot easier. To do that, click on the search filter button. Down here I like to click on the Only With A DMAS Entry because that just filters out sites that are really spammy. For sites that that have been in DMAS ever, it means that the site had to be of some quality.
They are easy to type and remember: You can’t get a easy to remember new domain name without paying huge bucks these days. Gone are the days where you can simply grab almost any incredible domain name just by paying a couple of bucks. This is one of the major reasons most people look for expired domains because most expired domains are short and sweet.
The following TLDs are now fully supported with a deleted list and a droplist (pending delete list). .hn, .ht, .rw, .cr, .gl, .gy, .gs, .om, .qa, .ir, .pe, .com.pe, .tc, .ky, .th, .co.th, .ke, .co.ke, .uz, .kz, .pm, .re, .tf, .wf, .yt, .sx, .gd, .gi, .kg, .mu, .im, .ug, .sb, .tl, .st, .sm, .so, .sn, .pf, .nyc, .cloud, link, .ms, .mk, .af, .bi, .pr, .com.pr, .nf, .nc, .dm, .bo, .ki, .iq, .bj, .am, .as, .ax, .fo, .mg