Yours is a complicated question.  In general the larger the sail, the lighter the material (lower wind speeds), the smaller the sail the heavier the material (higher wind speeds.  All in all the sails cast about the same regardless of size.  Cost = size x material cost (weight & fabric type).  

The next big question is how is the boat to be used:  day sail, coastal cruising, off shore cruising, passage making, and/or racing.  Will the sails be on furlers or have multiple sails changed on the fly.  

My best answer is talk with your sailmaker.  

<p> Hi,<br /> <br /> Fully agreed with the previous answer. I have since new a C36 TR from 1991.<br /> <br /> We being &nbsp;Cruising for almost 20 years, including Atlantic passages and cruised&nbsp;almost the whole Mediterranean.<br /> <br /> But since the last 10 years we just race the boat with almost no cruising.&nbsp;</p> <p> So<img alt="" class="image-medium" src="/sites/default/files/styles/medium/public/forum/62E035A1-F381-436C-86D2-A86CB5943CBE.jpeg?itok=NNd6Q207" style="height:220px; width:124px" /> now, our garderobe is full of racing oriented sails. &nbsp;So as said in previous comment, you have to decide what is your sailing program.&nbsp;<br /> <br /> Decide what you want to do a talk to your sailmaker. Just a personal advice, dacron is the more expensive cloth (many will disagreed...) I'm saying this because although is cheap to buy and last long, performance are lost after 2 seasons.&nbsp;</p> <p> Go for a good laminated material, and your sail will keep the shape for years. &nbsp;Just a thought.</p>