Interested in 80’s Submariners.

[IS2000]

Recently I’ve been looking at a few 1982 Subs (16800,5513) since I wanted to have a watch with my birth year. I found three different ones at Tokyo’s Nakano Broadway. They were priced roughly around 1.5-1.8 million Japanese yen. I believe none of them came with papers. I ended up not purchasing the watch on spot because I wanted to learn more about them first. So, what should I look for when buying these watches? I found a few more of them selling online from Tokyo watch dealers, but price ranges are quite high for similar watches without box and papers.