I may be a little late on this, but it's not illegal for a buyer to ask a seller to end an auction early and offer to buy the item for a set price. It's completely up to the seller what they want to do though. You still have a month until the show, I'd just wait another week then relist them.

FWIW, when I listed my Bon Jovi tickets for the second time (no bids on the first), I listed the $120 tickets at $49.99 and the $200 tickets at $59.99. Final bids on the both of them were around $199 and $201, so I was happy.