Whether sports or events, a key factor is buying tickets that stand out or are different in some way. You’re right on about being as careful and aware as possible about supply factors, such as promoters discounting tickets or announcing additional showings/concerts. You also make a very good and fair point about having capital tied up in inventory.
If you consistently fly with one airline you can fly any partner airline or airline that's in the same alliance with the same miles. For example, you can fly any SkyTeam partner with Delta Skymiles. You can search for award flights on the airline website by clicking the "Pay With Award Miles" button. Compare the actual cash value of the ticket to make sure you are getting a good deal. Even if you can only buy one ticket with your miles, that can still be a savings of a few hundred dollars.
In July 2015, Government of Ontario declared Ticket Scalping legal as an attempt to regulate online ticketing industry. Similarly in the US, each state has its own ticket reselling law. Some of the states prohibit the reselling of tickets, while some of them regulate it to an extent by mandating a license to resell the tickets. Hence, it is up to the Governments to decide if ticket scalping should be banned, based on the extent of vulnerability and business urgency.
When searching for airfare, most travel sites (Travelocity, Kayak, Priceline, etc.) allow you to make travel dates flexible by one to three days in order to guarantee the cheapest options. Some sites also have a calendar tool that highlights which days in that month or the upcoming months have the lowest fares. Switching your plans by a few days or to a different weekend might be inconvenient, but it can end up saving you hundreds in the long run. I’m a huge fan of Google’s Flight Explorer. Staying flexible is one of my top travel tips!
First, do your research: are there budget airlines unique to the country you’re flying out of and where you’re headed to? Booking with a budget Australian airline (Jetstar) from Sydney to Honolulu, then an American one from Honolulu to Montreal saved us over $400 each when flying back from Australia to Canada earlier this year. This allowed us to create a thrifty five-day stopover in Hawaii on our way back, which was less exhausting and a lot cheaper! Kiwi.com and AirWander are both great search engine for revealing cheaper routes like this that involve multiple airlines.
They don't. Especially on international fares, one of these online travel agencies could have a fare several hundred dollars less than or higher than another. Last April, Travelocity was selling seats to London on Virgin for $400-$470 round-trip, taxes included, from east and west coast cities, even for peak summer travel. Those fares were available on only Travelocity, not Orbitz or Expedia (they weren't even available on Virgin's own site). So check all the online agencies, including Cheapair.com, Hotwire, and Kayak, in addition to the ones already mentioned.
Nobody likes junk mail, but getting on email lists for your local teams and venues (or in other markets with which you have good familiarity) is the best way to find out about hot new concert presale events and discounts. Another benefit of being in the points/miles hobby is that often times Citi and American Express cardholders get special presale access (and sometimes discounted prices) to events.