Nice looking car. White R/T stripe nice touch.
Be sure to really go through the body in-depth (quarters, frame rails, floors, trunk floor, any bubbles around rear window SE insert, body panel misalignments, etc), and evaluate any previous bodywork and paint. If you have to redo anything there it's major unplanned cost (take it from me) on top of your purchase price. Other mechanical items can be done for containable cost, it's the body/paint that can skyrocket (unless doing it yourself).
If the body is good, and all the drivetrain and SE stuff is there (i.e. overhead console) then 50K plus or minus seems reasonable, but other experts will chime in for sure.