https://backpack.tf/item/1425648689 - sure it's spelled but it's voices from below, generally considered the spell that adds least (if any at all). I wouldn't immediately disqualify the entire item history just because of Voices from Below.

I believe the most effective approach is to gather sales data comprehensively, and subsequently assess the validity of the data. For instance, if a Voices from Below Tyrannus sells at 50 keys, one could argue that this price is inflated due to the presence of a spell and should be excluded. However, by first representing the data and then making informed decisions based on the overall range of sales, we ensure a more accurate and nuanced understanding of market trends.