Amazon has the Amazon Basics Chenille 42" W × 72" L Room Darkening Curtains (Pair; Grey Diamond) on sale for $11.24 with free shipping on $35+ or with Prime. Other colors are $12.49. 

• Designed for bedrooms, living rooms, and offices. Includes 1.5" rust-resistant metal grommets along top. 
• Machine washable (tumble dry low). Chenille fabric (100% Recycled Polyester)