Few if any sellers know anything about their bikes, and cannot use a tape measure either. Sometimes this can lead to a really good deal, other times, its just frustrating. I picked up three bikes last weekend: two were 22 inch frame size, the other was a 24 inch frame size. Seller insisted they were all "27 inch" frame size bikes.... Typical.
Shimano drive train means nothing as well. Almost every bike at Walmart has a Shimano drivetrain. Shimano made good stuff, and they made cheap stuff. Its all about what model Shimano.
It's impossible to tell what the bike is by the photo. It's either an 80's or early 90's Motobecane road model, but the seller's description is scant, and the non-driveside blurry photo doesn't give us much to go on.
That said, if it doesn't say Shimano 105, 600, or Dura Ace on the Cranks and deraileurs, it's probably not worth your time. I'd say anything over $200 you shouldn't even bother with. A Dura Ace or 600-equipped bike in spectacular condition for under $200 might be a good deal - it really depends on the bike itself. Any rust, dents, or dings in the frame, TAKE YOUR MONEY ELSEWHERE.
'72 Bob Jackson; '82 Austro-Daimler Starleicht; '85 Scapin; '80 Peugeot PKN-10; '81 Trek 610; '87 Hunter Corsa; '72 Italvega and '75 Motobecane Grand Jubillee frames built into freewheel singlespeeds.
Weren't Motos being made in Taiwan by this time? I agree with Maddox about the 1990-ish vintage (based on the fade paint job), and if that's the case $200 if it's in great shape, and your size, seems about right.
I have a Taiwan-built Motobecane made in 1981, so, yeah, they're definitely out there, but the Taiwan frames were nice lugged designs, albeit constructed of 2040 tubing. I'd be freaked out about the fact that this bike doesn't appear to have many of the original components, appears to have been repainted, and is probably going to be impossible to identify. Oh yeah, and I'd be willing to bet the frame is a 54.