Here's a design I just made up. Not sure how well it performs since I haven't made one yet because I have no place to set it up.
White = Frame, PVC (easiest & cheapest), Wood, Metal (Stronger, more expensive & time consuming)
{PVC = need T joints, 2 Y joints, (PVC diameter, height, & glue? is personal preferance)}
Red = Metal targets
Yellow = Chains, bungees, rope... (rear line is to hold target at a downward angle for deflection)
Green = Optional additional support arms for paper targets
Blue = Optional bar for misc targets
Pink = Misc. targets (Clays, Cans..)
If frame gets hit, quick fix is duct tape or replacement is still cheap but takes a bit time longer.
All together, stand should be less than $25, not including metal targets..not sure the cost of them.
An idea for a reactive explosion target is a balloon filled with some flour & rest filled with air. Should go POOFFF??
http://widget.slide.com/rdr/1/1/1/W/161b2660/1/50/eXGZ-lHG7j_EUc5QQHqQ2CcWB99fstYa.jpg