Honestly, I'd buy a new current pj, be happy and not waste time thinking about it, and buy a cheap bulb for the old pj for backyard movie nights with a portable stereo. Instant BBQ party HERO. Then you have great family memories vs a few hundred bucks!

Selling a super old pj is not even close to fair to the buyer. Cheap or not. They would be buying out of ignorance, and would feel quickly shafted once they learned a little.