I had Carolina Carports put up a 24 x 21 x 9 two Novembers ago...vertical roof, gables, and sides...12ga certified, which has 8 uprights and trusses.
I closed the back end with silver tarps from Harbor freight...I drove concrete form pins into the gravel, attached some aluminum angle to the top of the gable crossmember, and used 1" emt conduit for uprights...screwed the tarp to the gable crossmember at the grommets using big flatwashers...used bungees to pull everything tight...
this is second winter, and the tarps still holding up...even with some big winds weve had...
I have about $3500 in the carport