You are correct, it is quite difficult to sell any off plan property in the present economic scenario and same is the case with your property.
From what I have seen the going price in Sami Tower almost two months ago was around 900 AED/Sq.ft however it is likely that this has come down. Anyhow, in order to pull a sale quickly you would have to sell it at 10 to 20% below the ongoing price.
600AED might be at the lower end of the range and I believe you should ask for at least 700AED to begin with and take things further from there onwards.