To join, you’ll need to purchase an annual GoDaddy Auctions membership for $4.99 a year. Once you’ve purchased a membership, you can take advantage of member benefits such as our Auctions Tools, which can help you prepare before buying or selling any domains. After joining the auction community, you’ll quickly learn how to navigate the world of domain buying and selling and can begin to make money by investing in domain names.
1) pending delete auctions.  These are domains that were not renewed and are going through a pretty complicated drop process.  You can backorder these names at the auction venues and then each attempts to "catch" the dropping domain.  If one is successful you win the domain at $59 if you're the only one to backorder the name.  If more than one person backordered the domain a 3 day private auction is held.  Once the domain goes through the drop process, the back links have pretty much zero SEO benifit to the new domain owner.
Once you’ve settled on some domain name ideas, you can head over to a bulk domain search tool such as DynaDot’s to mass check all the names against different TLDs. When you’ve found one (or a few) good candidates, you can simply go ahead and register them for approximately $10 each. The next step would then be to market them. Then finally, it’s a waiting game.
That said, my recommended budget for beginners would be $500+. Using this budget you could buy a bunch of high-potential $10 domain names, expired/dropped domain names or a mix of both. It’s very important to invest only what you can afford to lose and treat this as a side hustle till you get the momentum going. As you gain experience, industry expertise and some sales under your belt, you can then consider slowly growing your business into a full-time gig.