Most bicycles sold in the US during the early 70s Bike Boom were described as "10 Speed Racing Bikes".
This looks like a standard fare entry level French bike made of 'gas pipe" tubing and steel components; nothing special or particularly collectible.
I don't recall the Fontan brand, it was probably one of the many private labeled marques produced in those days.
With a tuneup and new rear tire it will probably get you from point A to point B. These kinds of bikes sold new for around $75-$100.
Chas. Colerich Oakland, CA USA
Matthew Simon wrote:
> Found this on craigs list, and was wondering if anyone could tell me
> about this bike.
>
> http://denver.craigslist.org/
>
> Thanks again
>
> Matthew Simon
> Berthoud, Colorado USA