The first consideration when looking at a quilt is the design. Generally, more pieces = more expensive. As the pieces of fabric in a quilt get smaller, there is more sewing involved, therefore more labour intensive. The first quilt below would be an easier quilt to piece and the second involves more piecing because the four star blocks have many pieces of fabric to be sewn together.
|less fabric pieces|
|more fabric pieces|
|Triangles and diamonds|
So, without getting long-winded, that's the basics on quilt design and level of difficulty. There are many variations within each category and always the quilts that don't fall into any category, so look carefully at the quilts you are thinking of purchasing and learn to recognize and compare levels of difficulty.
Next time - applique quilts