http://www.tf2outpost.com/trade/9030224 got offered 1 ref for 10 dirties. basically paying 1 scrap each and gets a free dirty (probably lucky so won't include)

http://www.tf2outpost.com/trade/8414379 sold for 1 wep

http://www.tf2outpost.com/trade/6713597 Buying at 1 wep each

http://www.tf2outpost.com/trade/9035660 unsold at 1 scrap

http://www.tf2outpost.com/trade/8964229 unsold at 1 scrap

http://www.tf2outpost.com/trade/9043488 unsold at 1 wep

As there are only collectors buying this, i kept the range at 1 wep because of the rare demand. 1 scrap buyers seem to be rare so 1 wep is what i stayed at.