You'd need more than 3 links of them sold for 1.66, just because its in the range. Look for people buying at 1.33 and failing, or straight up offers of 1.66.

There is no link 4 :D

1.66 or over

http://www.tf2outpost.com/trade/6962344

http://www.tf2outpost.com/trade/6705971 (Gets offers such Vintage Stahlhelm, Strange RL & Strange DH, name tag & 0.33, 1 ref & decal tool)

http://www.tf2outpost.com/trade/6641129 (Got several adds)

http://www.tf2outpost.com/trade/6884871

http://www.tf2outpost.com/trade/5805125 (C/O 2 ref but 1 month old)

http://www.tf2outpost.com/trade/6860896 (1 sold)

http://www.tf2outpost.com/trade/6574184 (Offers between 1.33 - 1.66)

http://www.tf2outpost.com/trade/3539822 (Someone offers 2 keys but was 3 weeks ago, seller won't accept 1.33)

1.55

http://www.tf2outpost.com/trade/6841160 (Sold 2)

1.44

http://www.tf2outpost.com/trade/7081439 (Unsold)

http://www.tf2outpost.com/trade/7080427 (Unsold but rejects 1.33)

1.33

http://www.tf2outpost.com/trade/4905147 (Sold)

http://www.tf2outpost.com/trade/6710560 (Sold)

http://www.tf2outpost.com/trade/4904291 (Offer 1.33 accepted 2 months ago)

http://www.tf2outpost.com/trade/7103305 (1.33 offer rejected)

CONCLUSION

All the ones on sale at 1.33 are sold. Sellers will not accept 1.33 anymore. Plenty of buyers happy to pay 1.66.

This looks like a fair price, also see most trades at 1.66, some above, less below. Up