if you have the broken parts... you can fix it back.. as the mudguard guys will reattach it.. did mine 6 months ago... went to a friend's house living in a condominium.. parked my car at the visitors parking. and when i came back, part of my car's rear bumper was shattered, and it broke the top right mounting. so it was dangling on the right side. i collected all the debris, gave it to the mudguard guys. Voila. rm300 for reattached the broken bumper debris (like jigsaw puzzle)+put enforcement fibre glass on it+sanding+paint, at the damaged area.
and as for your case, it's at the lower part of the bumper. so it's easier to just install a lip spoiler there, to cover the missing part. but if you're going for the cheap way, you can do like what i did as long as you have the missing joint.