If they're using sCO international 752s for that then its not PS. PS on the sUA 752 has no economy minus seating and has business and first class, while the sCO 752 does have economy minus and only has business, not first.
The best bargain is using 50K US to fly in First on the sUA aircraft.
IIRC the new PS first seats are the same as the old CO 752 seats just they are putting in 28 seats
The new planes are 2 cabin configuration and the old planes they are using are being serviced as PS out of JFK only not EWR