I'm not really the one to be answering this since I've never liked vintage Peugeots, they flexed more than any other bike I've ever put a leg over, the Simplex stuff was the worst for shifting as well as reliability, and I've ridden the PX10's, also they were French threaded which turned off a lot of people.
Although the PX10's with the nervex lugs were the best looking bikes of the era, unfortunately yours does not have those lugs which would have made it worth more as would have 1/2 chromed forks and stays, it's also not the racing model which again would have made it worth more.
Not sure why the Peugeot (including PX-10) were so flexy since the better ones used 531 tubing, which my old racing bike was 531 but it flexed the least of any steel bike I was ever on (Trek 660 with 531cs).
However, there is one point on the bike that I could see from the photos which could distract from it's value but I think those Simplex derailleurs are Prestige LJ models, which were not that great, but I also noticed that one of the pulley cage bolts appears to have been sheered off and the nut missing, it appears to have been done recently since the sheered off part looks shiny, someone may have over tightened it and the bolt broke.
I couldn't find that exact model on catalog scans but as a guess I would say if that bolt is indeed sheered at around $100, if you clean up the gunk on the bike, polish it up, made sure the tire were in good shape, put on new cotton bar tape, everything was lubed and adjusted ready to ride you could ask $150 and get $125. The problem with that damn derailleur is that it is vintage and in short supply which drives up the price, used ones on E-Bay are getting $75, but (or if that bolt isn't broken, though it sure looks that way in the pics) if you can pull that bolt off the cage and find one to match it you could get away with a lot less money and then the bike could sell for $100 more then the prices I listed.
But if want to get the higher end prices that bike needs to majorly cleaned up and polished, along with all the other stuff I mentioned earlier.