Usually the trailer end of the awning is stitched along with the bag and the plastic spine that slides into the channel of the trailer roof.
Around here a bag awning can be had for $75 so maybe that answers your question. Or go to the fabric store and pick up the biggest sewing needle and some weather resistant thread then go to it!!
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.