The two things to consider when looking at a sheet set are 1) the material it is made with and 2) the weave or knit style. Materials are the fibers — raw materials not formed into fabric — and weave or knit as the form of construction used to make the fiber into a cloth. The same material can feel different depending on the weave or knit style, and the same weave or knit style can feel different depending on the material.
For queen size sheets, expect to pay anywhere between $50 and $300, depending on the style of sheets. In general, materials like linen and silk will be the most expensive. Cotton, bamboo, Tencel, or other similar materials can vary — some are quite expensive, while others are more affordable. Polyester and other synthetic fabrics will generally be the least expensive.
Duvet covers often have buttons, ties, an envelope flap, or zipper as a closure to keep the insert enclosed. It should be noted that a Duvet is the insert that goes inside the Duvet Cover; usually comprised of down or a down alternative. When the insert and duvet cover are together, sometimes it is referred to as a Comforter. It is common for Duvet Covers to have finishing details like flanges or embroidery along the side and bottom edges only.
Linen: Know Your Bedding Like a Designer