I agree with Anthony. Do you have a budget in mind at all?
Can you confirm if there is a text element to the logo or is it purely the sun image? Any extra details will be of great help to me and any other bidders trying to work out a price for your project.
Keep in mind that you have more chances to win a Job with Case Study as fewer Sellers will send a proposal. Moreover the Buyer has already paid a fee for it, which shows that they seriously intend to award the Job.