I never had any deflections with a basketball. I guess its possible. I use field points. I like to see the basketball jump with the arrow stuck to it when I hit.

For a cheap three-D course, I use stuffed animals that you can buy at second-hand stores or garage sales.  You can get all size, shape and colors.  And for fun rabbit hunt for the kids, use the stuffed rabbits all different colors hidden in the bushes and go hunting.  Have fun !

Burlap bag stuffed with the plastic sheeting used to line crawlspaces.

tennis balls and blunts

i used to use 1/2 washers hanging in the wind ,but kept tearing off feathers when the arrow rubbed the sides going through,so i went to a 1 inch now so my feathers dont get damaged,robin hood would be proud,,,,did that make anyone put there boots on,,,,,,,,jeff

I don't know if this qualifies as "cheap", it cost around $75.  The burlap sack target was $20 at 3-rivers. It's full of old rags which are everlasting. The landscape timbers could be substituted with scrap lumber to save $$.

I got this idea from an earlier post on TradGang.  I can't remember who posted it, but I tried it and it works!  (Thanks to the TradGanger who originally posted it!)

Fill plastic bottles with foam-in-a-can.  (I used 1qt juice bottles, and some 20oz water bottles.)  Stick an old shaft or stick in the mouth of the bottle after you fill it up with foam.  Once they have dried, just stick them in the ground or in a bale of hay or...

I suggest letting the foam dry a few days (or more) before shooting them, or that condensed sticky stuff will be a real pain to get off your arrows!  Trust me!    

The arrows usually penetrate about half-way through, sometimes up to the fletching.

PS:  I also spray painted the finished bottles a solid color, and then sprayed a small dot (of a contrasting color) on them.

A roll of  scrap carpet works very well and lasts a long,long time.

I just take an old t-shirt and tie it in an overhand knot, again and again until it's one big knot. Throw it on the lawn and keep shooting blunts at it. Doesn't ricochete or move around. Makes a nice pop sound when hit solidly. Arrows hit it and stop on the spot. The rag/knot absorbs all the energy.

I take a couple cardboard boxs and stuff them with old clothes. when the boxs start to come apart get a couple more and use the same stuffing over and over. arrows come out real easy.