So... I don't know what you want to do with this information, but I'll just report back.
I organized and sold a bunch of collectibles for a buddy of mine, and here's what I found...
I had 3 (or was it 4) Pink letters priced at 600 TBT, and it sold out within 3 minutes. And afterwards people were still asking for them, so the "market price" is somewhere above 600, I think.
I had 4 Green letters priced at 900 TBT, and again, same story, within 3 minutes of post going up, all sold out, and people were still asking for more. So, the real price is somewhere above 900.
I had 4 yellow candy up for sale, and they sold out within a day at 30 TBT. I think there are not that many yellows floating around right now, surprisingly? People are still asking.
I have 4 green candies priced at 250 and 3 red candies at 100... and still sitting there (despite being lower then guide prices). That's not surprising given that there are so many of those being offered, so, I'll let you know if they sell after I go even lower in price.