Email from StubHub that my World Cup order has been Cancelled

I'm at a total loss. Last week, I bought four tickets to see the third game in Guadalajara, which was announced yesterday as Spain versus Uruguay. When I bought the tickets, I paid $900 per for Category 4. It seemed high given the category, but there were plenty of tickets up when I bought. I just got an email that the seller is unable to fill the order, there are no replacements, and the order has been cancelled. When I checked, I now see that tickets start around $1500 per.

Is there anything now that I can do other than try again at $1500 and hope the seller doesn't back out?

If prices can go up and down, it's insane that buyers can't just back out if the market falls, but sellers can back out if the market goes up. What a broken product.