-snip-You will receive it when you get the entire blockchain downloaded completely and last time I checked it was 20 GB+
For the balance to appear, it does not have to be fully synchronized. As soon as the client has synchronized to the block which the TX was included in, the transaction will appear and you can spend it assuming you didn't use the wallet to send anything before.
-snip-
@OP, did you release the funds on ebay before checking for BTC payments?? Check it on a block explorer as mentioned above asap and never release funds before a Tx has atleast 3 confirmations.
For the latest Bitcoin Core, it is safe to accept transactions as valid at 1 confirmation, no huge risk for waiting any longer. Anyway, the TX has more than 100 confirmations right now.
I wouldn't recommend you to export your private key under any circumstances, it is quite a risk to do so. You have 2 options:
1) Wait for the client to synchronize and use it or transfer to another SPV client.
2) Generate a raw TX from a trusted service like coinb.in and send to your destination or another SPV Client.
1. Go to
https://coinb.in/#newTransaction to generate a new transaction.
2. Fill in your address and put your desired output. Remember to include a change address (if you didn't spend everything into one output), I would put my origin address OR directly transfer it into another SPV wallet and input the address in the SPV Address as the change address for the time being. And click submit and copy the text in the box.
3. Go to Help>Debug console>Console and key in this: decoderawtransaction [paste here #2] and ensure that the information is correct.
4. Key in this: signrawtransaction [paste here #2] and copy the text.
5. Broadcast it: sendrawtransacton [paste here #4]
At any rate, I will go with 1 if I don't need it.