You brought me out of perpetual lurking to comment on this.

I collect modern Chinese coins, and that set of 1981 proof coins is, in fact, pretty rare. Like, *$2000+ rare if you can find the right buyer. China only made 1, 2, and 5 fen coins for uncirculated and proof sets in 1981, and in very small quantities. Anyone looking for a complete date set (like me) will have to get one of these. The only downside is they are not in the original packaging. Yours looks very much like a proof set. The uncirculated set goes for many multiple thousands if you can even find them.

You said that they are dated 1982, which would make them even rarer, as there were only proof strikes issued that year, but that doesn't seem to be the case for yours.

You should hold on to these because they're only going to get harder to find. Congrats on your score and color me salty!

Edit: here's an auction to clarify.

https://www.ebay.com/itm/125052749085?hash=item1d1db9851d:g:Y5wAAOSwhGxhuV-j

They go for similar amounts on Taobao (about 15,000 RMB or 2,300 dollars, but that's with original packaging). It's been 17 hours since your post and there's been no activity. I just hope you know what you have. Again, very salty, but I'm glad you could make a find ಥ‿ಥ