Seller requesting 6 times the closing price on two separate auctions. Where to from here?

[soldaustralia]

I asked a seller if she would accept a $150 Buy Now offer for a window listed with no bids and at a listed price of $25 . She said yes.

Then I sent four requests to conclude the transaction offering advice on how it may be achieved and even recommending.this facility to ask other for advice if needed.

Finally, 34 hours before the auction closed I wrote and said I would not be available on the day the auction closed and that if the sale was not concluded by that evening, 20 hours before the auction closed, the auction would proceed and "we would both be bound by the outcome of the auction process".

I placed an automated bid of $311.000 and went into hospital Wednesday evening as planned. But on Wednesday night, got my daughter to ask about the condition of the window. There was no further communication.

Since the information was not provided the auction proceeded and closed Thursday evening with only one bid; my automated bid. The closing price was $25.

The seller did ultimately provide some bank details, which was not what I requested, but even that was sent just before the auction closed when it was apparent that there may be no better bid. And in any case, even if I had been there, they arrived after the close of the auction.

Next day, I won a second window at the same closing price; one on which I had made no offer. I paid for both windows immediately using PayPal.

Now I have received advice from the seller that unless I pay her $150 each for both windows she will cancel the auction transactions. She also suggests that I might be responsible for removing the windows from the building. This was not mentioned in the listing.

Where to from here? Any advice you may have to offer would be very much appreciated.