The demand was made following renewed interest from Celtic, with Neil Lennon acknowledging this week that the Iceland forward was still on his wishlist.
It is a fee which Celtic are unlikely to want to pay and the Glasgow club face strong competition for the forward, with Ole Gunnar Solskjaer, who was appointed Cardiff City's manager yesterday, understood to be among Finnbogason's admirers. Roma and Villarreal have also been linked strongly with Finnbogason.
The Icelander has previously indicated his desire to remain in the Netherlands until the summer but his agent is concerned about the fee which his current club expects to receive. "I found the price tag for Alfred unrealistic," said Kees Ploegsma. "It is clear that Alfred wants to leave."