Giving estimates for this type of work is not possible, yet home owners always want it. But this contractor over reacted and scared you. Something like this can only take more than a 15 minutes to find unless the electrician is not good at troubleshooting. About 45% of them are not. I know I have had up to 25 electricians on staff at one time. The rate seems reasonable, but need someone that can also give a reasonable estimate. The fix however could take up to 4 hours. The broken outlet is dangerous, but will not normally pop a breaker. What may have happened is that the broken piece also knocked the hot wire into the ground wire (most likely what is going on) and this popped the breaker. Turn of the breaker, not sure which one... turn off all breakers. Now remove the outlet and make sure no wires are touching any other wires. You may find one if I am correct. Then replace the outlet putting each wire on the same screw as you see on the old one. bare wire to green screw, white to nickle colored screw and black wire to copper colored screw. Wrap the wires clockwise around the screw.