There have been 16 sold on the Steam market in the past month that average out to about ≈11.9 keys. If you take out a mid-range outlier(33 keys), it comes out to an average of ≈10.47 keys. To have a more accurate average we could take out that outlier(33 keys) and add one mentioned below being sold for 26 keys(less of an outlier) and the average would come out to ≈11.47 keys. -This average is included in my final price range calculation.- The 17th one that was sold in the past month was sold for 62 keys, which is also a major outlier and was left out of all calculations.

https://steamcommunity.com/market/listings/440/Unusual%20Sinner%27s%20Shade

There were 11 sold on the Steam market the month before last month which averaged out to ≈8.9 keys.-This average is included in my final price range calculation-.

https://steamcommunity.com/market/listings/440/Unusual%20Sinner%27s%20Shade

4 are currently being sold on the Steam market between 9.8 keys and 11.13 keys. These aren't yet sales, but they fall within the common current price range. After that they take a hop up to extremely different prices such as 26 keys and 33 keys, which I consider to be on the verge of being outliers.

https://snipboard.io/kTACGi.jpg

Screenshots of the past two months of sales on Steam market:

https://snipboard.io/g3Moxq.jpg

A more zoomed in picture without the top of the item page in it, but obviously the same graph as the picture above: https://snipboard.io/CPeHql.jpg

Two are currently listed in classifieds and they’re both being sold for 8 keys. At first glance I believed both of these were “quicksells”, but given consistent sale data on the Steam market and the fact that they've been up for a fair amount of time, I personally decided they were not "quicksells". They haven't sold yet, so they are just supplemental data and not necessarily given any weight, but they both do hit the low end of the suggested price range.

https://backpack.tf/classifieds?item=Sinner%27s%20Shade&quality=5&tradable=1&craftable=1&australium=-1&particle=34&killstreak_tier=0

The average of the past two months comes out to ≈10.19 keys, which is near the center of the 8-12 key range that is suggested. Averages don't often include the low and high ends of what is being accepted in the trading market, which is why the suggested price isn't just 10 keys, 11 keys, etc. A range was needed.

6 sold within 8-12 keys within the past month.

5 sold below 8 keys within the past month.

5 were sold above 12 keys within the past month.

I believe the 8-12 key range to be satisfactorily accurate especially given that this item has no current bptf price.

If the range was made any bigger in either direction to include more sales inside the range, it would make the price less accurate and would be just as good as having no price. The range is already larger than what would be normally desired, but it is necessary and still small enough of a range to be functional.

If you have any extra data, feedback, or criticism let me know. Thanks!