There are too many "what ifs". Does your state require paperwork to be submitted for face-to-face sales between individuals? Are you required to register handguns? Basically, is there any scenario you can think of where you'd need to provide the serial number to someone in authority?
Also, why is the serial number illegible? Is it simple wear, or does it look like it's been defaced?
Regardless, $200 for a Springfield "Loaded" model is a screaming deal. Unless I had a bad feeling about my "buddy" or the origins of the gun, I'd jump all over it.