Lowes offers TrimmerPlus LE720 Edger Attachment for $20 (reg $100) with free shipping.

Product Description:
Part of the TrimmerPlus attachment system, the LE720 is compatible with CRAFTSMAN, Troybilt, Remington, and other attachment capable string trimmers from major brands. Edge your drive, walkways and flower beds quickly with the LE720 lawn edger. The 7.5-in steel edger blade provides a blade depth of 2.5-in for more precise edging and cutting. It is equipped with an easily maneuverable wheel to keep you in a straight path, and long blade for easy edging.

• Easily convert your CRAFTSMAN, Troybilt, Remington, and other attachment capable trimmers into an edger
• This attachment is equipped with an easily maneuverable wheel and long blade for easy edging
• The 7.5-in steel edger blade provides a blade depth of 2.5-in for more precise edging and cutting
• The adjustable blade reaches depths up to 2.5-in and the angle of the boom allows the user a clear and easy viewing path
• Constant torque gearbox is rugged and durable
• Backed by a 2-year limited warranty