where exactly is some true evidence? none of those were accepted.

Second link apparantly sold for 0.66 ref, last link had a recent offer of 0.66 ref- though the offerer apparantly got it elsewhere in the meantime.

http://www.tf2outpost.com/trade/5111857- Very recent 0.66 offer for a strange brass beast

http://www.tf2outpost.com/trade/4982348- Negotiated to 0.55 ref

Offers of 0.33 ref for it are EVERYWHERE, which indicates it's a lower point. I agree the strange brass beast is climbing a bit and I think this is a very good range.

the second link says someone sold one for 1ref

It seems to be going mostly for .33. I might see it being raised to .33-.55, but not .33-.66. There just aren't enough accepted trades for the latter to be considered a standard asking price.