That looks like an 82/83 Peugeot PSV.
A much desired upper mid level race bike by 80's Peugeot fans, but it seems like your example has had a few of its components changed out from original.
The rear derailleur should be a Simplex model SX610
The stem should be an Atax brand quill style stem.
Brakes, shifters, front derailleur and saddle sounds original.
Does it have the original wheelset on it too?
I emphasized originality as the bike is prefered by most buyer as original as it could be. On the contrary, you will not get too much value back too if you start hanging really expensive components on it considered to be above the bike's worth. If you still have the original components from the bike. It might be worth installing them back on it to get full value.
As it is, with best condition paint/finish, your PSV might bring $275 to just below $300 max on a really good day. PSVs used to bring in $350 easy about a year and a half/two years ago, but the depressed C&V market had lowered its value in most markets, but you might be able to go over $300 as-is if you sell it in a really hot bike market like Seattle or San Francisco/bay area...which I just noticed, you turn out to be from.....so that's good news! So try to sell local if you can.....That might get shipping out of the deal (local pickup?) and the buyer might be willing to go just a bit higher on the price.
Good Luck!
Chombi