Excerpted From 
Jan David Winitz, eminent rug expert and president/founder of Claremont Rug Company, has developed the Oriental Rug Market Pyramid™, a guide to support those interested in purchasing Oriental rugs. Rankings in the six-level rug Pyramid are based on artistry, craftsmanship, quality of materials, condition, age and provenance.
As the tiers descend, the number of available pieces increases significantly, while the artistry and originality generally decreases. Rugs in Level 1 are held primarily by museums. Art-level pieces are found in Levels 2 through 4. Rugs in Levels 5 and 6 would be considered durable floor coverings of no intrinsic art or investment value.