Buy orders at 21+ keys, which is above the current range.

Item Sales:

Can't find any.

Last month on Marketplace.tf:

August 31st: Sold at $47, $1.86 per key = 25.3 keys

August 29th: Sold at $45.54, $1.85 per key = 24.6 keys

August 27th: Sold at $45.54, $1.83 per key = 24.9 keys

August 24th: Sold at $29.85, $1.81 per key = 16.5 keys

August 8th: Sold at $43.33, $1.87 per key = 23.2 keys

August 8th: Sold at $39.00, $1.87 per key = 20.9 keys

July 28th: Sold at $45.54, $1.92 per key = 23.7 keys

July 21st: Sold at $45.54, $1.95 per key = 23.4 keys

Last month on SCM:

September 14th, 7PM: Sold at £55.03, £1.78 per key = 30.9 keys

September 13th, 2PM: Sold at £35.99, £1.77 per key = 20.3 keys

September 6th, 10PM: Sold at £36.03, £1.78 per key = 20.2 keys

August 31st, 12AM: Sold at £46.45, £1.82 per key = 25.5 keys

August 22nd, 10AM: £44.41, $1.80 per key = 24.7 keys

Ignoring sales below 21.5 keys because of the buy orders. Closest sale above 21.5 keys is 23.2 keys, so that is my lower bound. 30.9 keys looks like an outlier; the rest seem valid. So, the range is 23.2 keys - 25.5 keys.