The PP fares are all over the place. Planning summer and fall trips the upsell can be as little as $200 over an S fare and as much as $1,000. Even if it appears the cabin is empty based on seat map (I know it’s not an indication), some flights just don’t have R space. And it’s definitely route specific. Looking to go to Frankfurt but the nonstops don’t have R fares, only As and Os. But connecting on the same flight to somewhere else in Europe on LH in Y, R pops ups.