Super LeTours are really nice bikes. Easy to work on with standard parts that are easily replaced or upgraded as needed. Peugeot on the other hand has many unique french threaded parts which are a little more tricky to work on and replace when it becomes necessary.
$200 for a PX-10 is a real bargain. In good original condition they regularly sell for upwards of $500. A Super Letour pretty much tops out at $200. If its in very good condition with excellent paint maybe a bit more. To a casual observer a Peugeot UO-8 looks like a PX-10, especially if its white, and for some reason more people know the PX-10 model designation. The UO-8 is a nice model unto itself but the value is much less, perhaps $150 in good condition. And there are some who look for UO-8s as they have a certain french charm to them.
Getting a true ID on the Peugeot is required here, before you make a decision.