OK, pretty limited options at this point really. Three altogether from what I can see.
1. Find another supplier at a better price
2. Cancel the orders and refund the buyers
3. Take the hit on your own pocket and complete the transactions.
Number 1, chances of finding a dropshipper offering a much better price would be low I would suggest. You also have the time limit of finding one as a concern at this point as well
Number 2, the only real option of getting out of it at no financial cost to you in my opinion. Of course if we are talking about eBay here, then maybe some cost feedback wise and if your account is only new, then you have to be very careful about that sort of impact on a new account.
Number 3, if you value your eBay account and don't want to risk the chances of collecting a couple of negs is the option I would recommend. Take the hit financially and book it down to experience.
Outside of those options, I really have no other ideas on this one.