Pretty much all parts need updates but their markets are just too small.

No sellers on the Classifieds, and only two sellers on Outpost, one is selling for offers, and one is mass selling them at 4 ref each, with no sales I can trace.

SCM also calls for a raise, selling at an average of about 30 cents USD, which is equivalent to 1.66 ref http://steamcommunity.com/market/listings/440/Strange%20Part%3A%20Medics%20Killed%20That%20Have%20Full%20%C3%9CberCharge

Recent sales:

http://www.tf2outpost.com/trade/24044399 The only sale I can trace in the past week, sold in less than a day at 1 ref

Offers:

http://www.tf2outpost.com/trade/24026356 Got an offer at 1 ref in less than a day, which got denied.

Buyers:

http://www.tf2outpost.com/trade/23777640 Unsuccessful at 0.66 for 2 weeks

http://www.tf2outpost.com/trade/23630714 Unsuccessful at 0.66 for 4 weeks

http://www.tf2outpost.com/trade/23437408 Unsuccessful at 0.66 for a month

http://www.tf2outpost.com/trade/22332744 1 ref

http://www.tf2outpost.com/trade/23922563 1 ref

http://www.tf2outpost.com/trade/22718076 1 ref, for 2 months!

Even thought 1 ref alone is probably a bit on the low side, considering how many buyers there are for it at it up unsuccessfully, but it is definitely the most common trading point, and it is virtually impossible to get for less.