It could be, just depends on what kind of condition it's in... If it hasn't been screwed up by some hack, then it's probably a good deal.... If someone tried to do some work on it, and it may take $500 to sort out, then it may not be so good.
Do a good visual, and function check, including the pencil in the barrel, since it may be a Series 80. Make sure all the safeties are opertaing properly, that the serial number looks proper, and not altered, and you may check with local Law Enforcement, and see if the serial number is listed in NCIC. Sometimes, a good price is too good to be true.
Be safe, and be careful...