How does express trading work for purchase requests?
In your account settings you can specify that your purchase requests should be highlighted if there is sufficient credit for express trade. There is no possibility to create a purchase request that can only be processed via express trading.
Please check the Express-Trade-Settings of your account under 'my Bitcoin.de' -> 'Settings' -> 'Express-Trade-Settings'. It should be specified here, that your purchase requests can only be processed via express trading, if sufficient balance is available.
Continuative Information:
How can I make my own purchase request on the marketplace?