Ok, the problem seems like a clear-cut supply-and-demand one. So if artists don't want to look like a bunch of greedy jerks selling tickets for $500+ apiece, and there's only so many seats in the venue, why not increase the number of shows? Maybe the venue is too booked-up and the artists get too tired playing the same venue 5 days in a row and being on the road 5x as long, but it's a thought.
The other question I have is: decades ago, concert tickets didn't cost this much, even after adjusting for inflation, and that's when rock bands were in their prime. What happened? I'm pretty sure it didn't cost the equivalent of $500 to see Led Zeppelin in concert in the early/mid 70s, so why does it cost so much to see U2 (an old band now) in 2017?
>> decades ago, concert tickets didn't cost this much
I'm willing to bet it's because in the old days artists could release a record and make a living from that without even touring. Now the record, for most artists, is a promotional tool, maybe even a loss leader, for concerts. As for 'why don't they just play more shows' I'd say the reason is quite similar. In the past artists didn't have to tour enough. Now they tour for incredibly long periods of time so they can extend that further (unhealthy and maybe even impossible) or play more shows in fewer places.
Take a look at Kate Bush for example. Didn't tour for 35 years. Most artists will perform but there was definitely an era where it wasn't necessary to putting food on the table.
The other question I have is: decades ago, concert tickets didn't cost this much, even after adjusting for inflation, and that's when rock bands were in their prime. What happened? I'm pretty sure it didn't cost the equivalent of $500 to see Led Zeppelin in concert in the early/mid 70s, so why does it cost so much to see U2 (an old band now) in 2017?