A little bit of a pain to price. 1 on the market, 2 in existence, and I found the second one by accident.

http://www.tf2outpost.com/trade/21787542 (Trade happened before 3 months was up.) ~ Sold for a Smoking Marauder = 1 * 0.9 = 0.9 buds

http://www.tf2outpost.com/trade/23299376 ~ Sold for 1 bud + 3 keys + some 2 ref spell = 1.2 buds at that time

http://www.tf2outpost.com/trade/22325847 ~ 'Quicksold' for 1 bud + Bill's = 1.2 buds after overpay at that time

http://www.tf2outpost.com/trade/22641358 ~ Sold for 1 bud + 4 keys + 3-4 keys in sweets = 1.4 buds after overpay at that time

First sale seems like an outlier. At that time the Marauder had a price range of 1.3 - 1.6 buds.

Feel free to counter or support my proofs.