If all that you are looking for is a cheap set of stands I can discribe the design that I've used for years and cost about $8 and 20 minutes to make out of PVC piping.
Base is 2 ft by 4 ft.
Cut 6 tubes of 1 1/2" PVC to 24"
Cut 2 tubes of 1 1/2" PVC to 8"
Use 4 1 1/2" 90 degree joints to form 2 'U's
Join the 2 'U's together with 2 'T' joints with the 'T' base pointing up
Place the 8" tubes into the 'T' joints.
I filled the bases with some left over Drywall Mud for stability.
You could leave the joints un-glued for ease of breakdown/transport.
Target Frame is 2 ft by 6 ft.
Cut 4 tubes of 3/4" PVC to 36"
Cut 2 tubes of 3/4" PVC to 24"
Use 2 90 degree joints for the top corners.
Use 2 'T' joints for the mid frame joints and cross bar.
Cover the resulting rectangle of PVC with cardboard for backing.
Add a target and step to the line!