Price of the Strange Festive Ubersaw should increase slightly. Evidence/Proof posted below. I will close this suggestion if there are too many disagreements.

Backpack.tf Classified Listings

http://backpack.tf/classifieds/search/id/520152abba25361b0b000006

One at 4 Keys and another for 4.5 Keys

Steam Community Market

http://steamcommunity.com/market/listings/440/Strange%20Festive%20Ubersaw

Strange Festive Ubersaw - Steam market average (24 hours): 11.50 USD (2 sold)

Mann Co. Supply Crate Key - Steam market average (24 hours): 2.44 USD (2920 sold)

Price of Strange Festive Ubersaw in Keys when bought from Steam Market - Approx. 4.7 Keys

Some Trades on Outpost

Some Offers and Sellers

http://www.tf2outpost.com/trade/13541876 - Interested buyer for 5 Keys?, 1 Day ago

http://www.tf2outpost.com/trade/7829910 - Willing buyer of Approx. 4.33 Keys, 1 Week ago

http://www.tf2outpost.com/trade/13483319 - Offer of 4.33 Keys and 3.66 Keys in the past week

http://www.tf2outpost.com/trade/14760730 - Sold for 4 Keys

http://www.tf2outpost.com/trade/14754051 - Offer of 4 Keys, 1 Day ago

http://www.tf2outpost.com/trade/14602144 - Offer of 4 Keys, 1 Week ago

http://www.tf2outpost.com/trade/12890240 - Already sold, but 4 different people are willing to pay 4 keys in the past week

Some Buyers

http://www.tf2outpost.com/trade/14459073 - 4 Keys, 4 Days ago

http://www.tf2outpost.com/trade/14766496 - 4 Keys, 2 Days ago

http://www.tf2outpost.com/trade/14788874 - Essential Accessories (Approx. 3.75 - 4 Keys Value)

http://www.tf2outpost.com/trade/14721774 - Approx. 3.8 Keys, 5 Days ago

http://www.tf2outpost.com/trade/14389834 - Approx. 3.66 Keys with 1 interested seller, 1 Week ago

http://www.tf2outpost.com/trade/14671390 - Approx. 3.66 Keys with no interested sellers, 6 Days ago

http://www.tf2outpost.com/trade/14793745 - 3.5 Keys with no interested sellers, 1 Day ago

http://www.tf2outpost.com/trade/14790465 - 3.5 Keys with no interested sellers, 1 Day ago

http://www.tf2outpost.com/trade/14762885 - 3.5 Keys with no interested sellers, 2 Days ago

http://www.tf2outpost.com/trade/14411411 - 3.5 Keys with no interested sellers, 2 Weeks ago

http://www.tf2outpost.com/trade/14167572 - 3.5 Keys with no interested sellers, 4 Weeks ago

http://www.tf2outpost.com/trade/13411034 - 3.5 Keys with no interested sellers, 1 Month ago

Some Trades on Bazaar

Some Buyers

http://bazaar.tf/trade/453192 - 3.5 Keys with no interested sellers, 4 Days ago

http://bazaar.tf/trade/397730 - 3.5 Keys with no interested sellers