Walmart has Decathlon Forclaz Trek700 Ultralight Insulated Camping Sleeping Pad (L or XL) on sale below for prices starting from $8. Shipping is free w/ Walmart+ (free 30-day trial) or on orders of $35+.

Available:

• L (70.9″ x 20.5″) $8
• XL (76.8″ x 23.6″) $9.33

Features:

• Mouth inflation.
• Efficient 2-way inflation valve with anti-return.
• Comfortable & thick sleeping surface.
• Anti-slip silicone pads. Limits the sleeping bag from sliding.