Hardware Sales Inc via Amazon has 4-Pack Kreg KHC-1410 Automaxx Heavy-Duty All-Metal Face Clamp with 3" Reach on sale for $49.99. Shipping is free.
Editor's Notes & Price Research
The Kreg KHC-1410 Automaxx Heavy Duty All-Metal Face Clamp can fit any size up to 2-7/8" and is compatible with multiple Kreg tools: Kreg Jig, Kreg Portable Base, and Kreg Jig Jr. The new auto adjust technlogy automatically adjusts to any thickness. - brisar
MSRP is $30 a piece, street seems to be around $25/ea, 4.5 stars on Amazon (on the single item listing).
Edit: the 6" reach version is also available for $35/pair or $60/four
Kreg seems to have came out with an updated design "Wood Project Clamp" so this seems like a leftover sale.