nice purchase! the cars seems to be in shape. things to consider first!
For restoration firstly make the car 100% mechanically reliable. Get the Engine Checked properly for work, change all the fluids and get the radiators serviced. Service the brakes (change the oil, brake pads and shoes), change all the belts. get your suspension checked and repaired and get the electrics done from someone who knows how to work on electrics.
then you can for the denting and painting! best of luck
Cost of restoration depends upon what sort of parts you install and what quality of work you want.