Colnago is probably the most common pantograph, IMO. that said, prices on Colnago-panto stuff varies a lot, depending on the part, the manufacturer, the age, and the most unpredictable variable, demand.

being that this is a nice classic Campy Record Strada crank, it's on the more desirable side. i'd say its value is anywhere between $100 (a great deal) and $250 (a rip off). If you can get it for under $200, then go for it.

two side notes: complete groupsets with Colnago pantographs on everything tend to pop up every few months. they're typically Campy Record of the 80's vintage. they usually sell in the $1000 range - pricey but worth it if you're of the "gotta catch 'em all" mindset.

also, if you're buying this crankset from France, make sure it's compatible with your bottom bracket. there's a possibility that it may only work with French BB's.