First time receiving a 1099-k. Have questions.

So, I have season tickets to a popular sporting team, and, we are now allowed to sell them for a profit on ticketmaster. So, for argument's sake - I paid ~4k for my tickets, and, I was paid out a net total of ~11k USD. I figured, hey, I'll end up taxed on 7k profit - no big deal. Anyways, I got my 1099-k from ticketmaster and I was floored when box 1a reported nearly 14k! I called them up and they said this included the total gross sales, and not the net payout received. For instance, if I list a pair of tickets for 1000$ - they take 10% off the top, plus the charge to buyer a bunch of fees. I, myself, only receive 900$. They sent me a spreadsheet with the fees they took from me, as well as the fees they charged the buyer of my tickets. I am assuming I don't actually have to pay taxes on the 3k I didn't receive, and there's a way to notate (perhaps schedule C?) that I indeed:

 

1. Paid 4k for my tickets.

2. Ticketmaster accounts for 3k of said total in box 1a.

3. I only really profitted by 7k.

 

It wasn't obvious to me when I was kind of poking around. Please let me know if my assumptions above are correct, and, where I'd go to handle this pieces?