How do I correctly treat this transaction?

I suppose the problem is you have an event with a maximum ticket capacity. You sell tickets where the ticket itself has near zero value but when sold you created a liability to be paid to the artist (or their agency) and you are entitled to your commission.

For one off dividing up the $1000 payment from the customer and dispersing it into a commission income account ($200) and an artist liability account ($800) would make sense.

Not sure how best to do something similar for many tickets.

Managers non-inventory item functionality may help but I have had not need to use it so don’t really have any idea.