jjhabbs 

I was once told that to these campagnolo shifters are rare. I heard they're from the 50s. The C in campagnolo is open. See the picture. Wondering what they are worth for a pair.

JJ

repechage

These levers would be paired with the clamps that use the black oxide backing plates with the cable stop port, all metal internals, small text on outer compression washer AND a screw, no ringed bolt.
They are marketable, not everyone will go into the minute detail.
$20 a left and right pair would find a buyer I think. Beyond that?

Drillium Dude 

Agree with this sentiment. Ebay is a wonderful research tool for establishing baseline values, and that's where I always go to get an idea of what the old stuff is going for. I also, from time to time, check to see what kinds of prices Boulder Bicycle has up on their website. Sometimes their pricing seems spot-on, other times bscene - but Ebay does the best job because it represents a global marketplace. I can list my "widget" for $100 tomorrow, but it's not worth that until somebody pays the asking price.

DD

Kabuki12

eBay is a great resource but sometimes things sell for super low or high prices for no apparent reason so definitely use an average.

Mad Honk 

Current prices are $23 to $45 for complete clamp on shifters. Smiles, MH