Forum wise? Not so much that I could recall right now, nowadays, one could use Discord and use #price-check channel to see what others are selling for. I remember there used to be a price guide on Discord a while back for the base gems of say Blue Sapphires, Emeralds etc and then it eventually included newer gems and seasonal dyes. Try there and see what you can find out.

As said above, Discord is definitely the place for discussions on prices! Selling stuff is also a lot easier in general, as you'll have a channel to advertise your things and offers are a lot better (in my opinion). Pricing stuff has gotten so much easier since joining and seeing proper discussions on what's popular and what's not, what people are generally willing to spend on that sort of thing, etc.

Check the community tab if you need the link to join:)