Recently i have sold a nnb veil for a non duped lvl1/7 max in 20 hours:

http://www.tf2outpost.com/trade/11904539

and a quick-buyer has offered 1 bud + 12 keys for it

other trades:

http://www.tf2outpost.com/trade/8710101 multiple 2 buds offer in one week

http://www.tf2outpost.com/trade/11752534 has offers of 2 buds 5 days ago

http://www.tf2outpost.com/trade/11460840 has offers of 1 buds 20 keys. but user is not pumping much.

in my opinion, 1.5-1.8 is rather a quick-sale price. It can be easily sold for 2 buds.

If you are feeling that my evidence is not good enough, i will be willing to get more into it