I have the same bike...well, maybe a size smaller....mine is about a 1980 model. Weinman center-pull brakes, Motobecane labeled (SR stamped?) triple crankset, Suntour VX in rear, 5 speed 14-32 freewheel, Selle Italia seat, one set of cage bosses, no bosses in fork, etc. stem/steer tube is the French (ie, smaller) diameter...don't know about threading on the BB because I didn't compare mine to another one. I pulled mine out of a shed for $0, completely dismantled, cleaned, polished, repacked all the bearings, added new tires, tubes, fenders and some accessories and it has come back into "play" as a very nice riding bike that I commute with, take on pleasure rides, or whatever....I liked what a friend said about it when he looked at it,....."I guess 'grand' is French for Hotel"....true, but still a great bike. I also have one of the same model, but an '84, thus 18 speed and different drivetrain, that I bought from an ad on CL for $100...it was clean, tuned, and literally ready to ride (I love buying bikes from neat freaks!)....so, one could argue that I over-paid for the one I pulled from the shed. But, hey, I like blue and the other one is gunmetal/burgandy
That's a long way of saying that I've watched these a lot since I own two & my observations are they seem to be sold pretty cheap (or advertised cheap), but are very nice riding bikes. In the condition shown, I wouldn't get into a bidding war, though.
Here are mine:
and...
