Bent Peugeot Carbolite 103 Frame
It can be fixed. I can't guess how much your local bike shop will charge but any good shop should give you an estimate plus or minus 10% of what they will charge so you will know what to expect. 

Here is an article at Park Tool explaining how to align a frame. It is possible to align a frame at home and get it kind of close even without shop tools if you have some skill. Some have used a string to measure alignment instead of the shop tool.     

Once it is fixed it should be safe to ride assuming the rest of the bike is safe (see my note below).
From Sheldon Brown  


  A steel frame can be straightened (within limits) if bent, and still remain safe and strong. 


NOTE: I am saying that a steel frame that has been straightened is safe to ride assuming the rest of the bike is safe.
Since I can't assess the over-all condition of your bike I'm not saying that your bike is safe. Your local bike shop can make this assessment and would be able to speak to the over-all safety of your bike.