Concert ticketing is a huge mess. I looked at creating a startup in that space before my current startup.
Ticketmaster/LiveNation control 70% of the market (in the US and UK; to a lesser extent elsewhere), this is though a mixture of owning or having exclusive contracts with big venues and having exclusive contracts with artists.
Venues make almost nothing from the tickets, for a big artists the artist will take a huge cut of the ticket price (often in the 70-85% region). Venues make all of their money from selling in venue products (food, drink) and a cut from product sales (tshirts, etc.) So it's in the venues interest to get as many people in as possible, venues would love to do dynamic pricing like airlines do.
But they can't, they're restricted by the contracts with the artists. Those contracts are very tightly written so venues cant do auctions to make more money or sell excess tickets at discount. It's also a reason places like ticketmaster have weird pricing, they can't just change the price of the ticket to be inclusive of all their fees.
Ticketmaster/Livenation for some time have wanted to run a discounted ticket site but it means renegotiating tens (if not hundreds) of thousands of artist and venue contracts, it's a non-trivial task. The whole thing is a huge mess.
Most startups in this area have tended to concentrate on the secondary market where you have less of these problems, but even there you need a lot of money to break into the market. It's very advertising driven (ticket sites are one of the biggest users of affiliate sales) and there's a huge amount of credit card fraud in the space so you often need to post a huge bond to even get a merchant account.