Hey, the possibilities are endless when it comes to domain flipping so do not think that all profitable domain names are already taken. At this time, almost 90 million .COM domains have been registered, so people tend to think that there are not many good domains left. That is not true since you still have the opportunity to incorporate two or three word target keywords.

There is a common misconception that domains expire on their expiration date. If a domain registration is not renewed by its expiration date, the domain simply goes into "expired" status, which means all services are shut off. Typically, we provide a 35-day grace period during which the current holder can still renew it for the standard renewal fee. For more information please review our domain deletion policy.
Namejet is a domain clearing house (at least that is my term for it).  What happens is that people let their domain names expire everyday.  Some people just don’t need their domain anymore, some people forget to renew it, some people die, I mean there can be hundreds of reasons why a domain will not be renewed.  What the domain registrars want to do is cash in on the domain that someone forgot to renew, so they offer that domain to Namejet to auction it to the general public.  Think of it like a storage unit, someone doesn’t make their payment and the storage company hires an auctioneer to come and auction the storage unit to the general public.  Namejet is doing this but for domain names.  The bid for each domain starts at $69.  What I LOVE about Namejet is the process…  they let you search through the domains that are coming up for auction 30 days in advance.  Whoever places a $69 bid on a domain will be entered into an auction when the 30 days runs out with everyone else who placed a bid.  If you are the only bidder than you get the domain for $69.  If there are 10 other bidders than there is a closed auction, meaning only you 10 guys can bid now against each other in a 3 day auction with the highest bidder taking the domain when the clock strikes zero.  I love this because let’s say there is a great domain and it flies under the radar.  If it goes to auction with only 3 or 5 or 7 bidders my chances of winning this domain at a very low price are great.  I’ve won domains for $100 which I was able to flip for $2,000.  I won a domain for $2,500 which I flipped within 4 months  for $7,500.  I won a domain for $1,000 which I’ve turned down $5,000 offers on because I think I can get $10,000 for it.  The key is to not overpay in order to leave yourself plenty of room to turn a profit when you flip the domain.

Most popular auctions with expiring domains are at godaddy, namejet, snapnames. Search for expired domains name its very easy if you have domains list. With a bit luck, you can drop good one with PR5 cheaper like $200, just need to know which domain have not fake pr. List of domains are not free, but updated dailly with aprox. 50.000 new expiring domain names.
With over 25 million .com domains registered with Google alone, this top-level domain is by far the most popular choice worldwide. According to the domain marketplace Sedo, the average sales price for a .com domain name during the second quarter of 2015 was 4,701 dollars. The most expensive publicly traded domain names have been known to fetch eight-figures. But don’t quit your day job just yet: such sales are the exception rather than the rule.
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.