Ask the dealer to provide you with the estimated costs for the PMS for the first X years and Y kilometer, then compare with that of an alternative choise like the Kia. Spare parts will obviosly only be available from the dealerships, because it is a niche model not a volume seller like an Innova or Montero etc. But that is actually also the case with the Kia Carens, so in that respect they are just the same. The good thing about purchasing spare parts from the dealership is, you are sure, they are orignial and live up to the manufacturers specification. That is not the case, if you buy cheap copy parts from an auto parts shop.
The real problem with Peugeot perhaps, is the risk that they will shut down business and leave the country again. That has happened before in the wake of the asian financial crisis in 1998, which saw sale of new cars plummet to half their previous peak. But maybe / hopefully the 2. time is the charm for Peugeot, and the new car market wont be hit with such a hammer again anytime soon? That is a matter of faith and a decision, you can only make yourself.