I paid almost nothing for my 1983 nighthawk SC550, and I've spent maybe $1500 on powder coating, paint, and plating, then I had the carbs rebuilt, new handlebar and all new controls and switches, brake and clutch lines, tires, headlight, tail and turn signals, and seat.
I'ts been a project to say the least but I've enjoyed it, and thank goodness I'm almost done, so I can san start on my other one a KZ650.
good luck, and plan it out.