Paypal service temporary unavailable for Pay Now button.
Most of the Sellers and buyers face this payment problem. After winning an item, when buyer click on Pay Now button the message appears Paypal service temporarily unavailable, please try again later.
There is no definite rule for occurrence of this problem.
Some buyers succeed in first attempt, some in third or fourth attempt whereas in most cases the problem remain unresolved even after weeks.
This affects sales of sellers & also causes lot of problem to buyers. I talked to Paypal about this problem and they told me that this is common problem occuring world-over to many account holders.
You need to manually send money request to all your buyers through paypal. To do this open your paypal account & click on Request Money. Write the email address of your buyer with bid amount and other details of your listing including Title, item No. etc (all this information can be obtained from your listing on ebay)
Also send message to your buyer instructing him/her to log-in his/her paypal account to make the payment from paypal side instead of relying on Pay-Now Button on ebay. This is the only solution to this problem so far. Although Paypal claims that they are working to solve this problem, but there is no definite period announced as when this problem will be solved.