Walmart offers Allen Sports Deluxe 2-Child Bike Trailer for $89 (reg $149.99) with free shipping.

Product Description:
Take the little ones on an adventure with the Allen Sports Deluxe 2-Child Bike Trailer. This accessory makes it easy to take the kids on a ride, while remaining safe for all within. This Allen Sports 2-child bike trailer has oversized front and side windows so the passengers can look out at the world whizzing by. It also features a footguard to protect their feet as well as padded 5-point safety harnesses to keep them comfortably in place.
Allen Sports Deluxe 2-Child Bike Trailer - Green:

• Safely and comfortably transports up to 2 children (100 lbs. max. payload)
• Allen Sports 2-child trailer has lightweight steel construction
• Durable quick-release 16" steel wheels
• Oversized front and side windows
• Footguard tube protects passengers' feet
• Padded 5-point safety harness comfortably holds the child in place
• Folding design with quick-release wheels