With due respect, but what are you basing this statement on (that a total refit would be very expensive)? In 2011 SAAB recieved the contract from the Thai to perform MLU (OF weapons and electronics) for 2 Thai Navy Naresuan Class frigates (Chinese Type 053) for a total value of $72M ($36M per ship). This included Mk41 VLS, new secondary guns, Saab’s 9LV MK4 combat management system, Sea Giraffe AMB 3D long range air surveillance radar, CEROS 200 fire control systems, EOS 500 electro-optical system, Tactical Data Links (TDL’s) for communications with the newly acquired Royal Thai Air Force Erieye surveillance aircraft, a new sonar system, a new ESM system and a few other improvements. That could put the F-22p upgrade (if pn goes with slightly better system and adjusting for some inflation) at ~$35-$40M/ship, meaing ~$140-160M for all 4 ships (less than the cost of J-class for similar performance).
Now
@Rafi can correct me but this seems to be exactly in the same vein as what PN would need l, except it may require less changes (secondary guns and AShM, and Sonar dont really need to be changed for F-22P), and given they are likely to source many electronics (like Genesis Advent CMS) from Turkey to improve interoperability of the fleet (F-22p and J-Class) the cost may be near if not less to what Thai paid the swedes for some things. The big issue would be sourcing the VLS/SAMs. I hope that we will be surprised by Italians and MILGEM/J-class would be equipped with CAMM-ER, in which case, F-22p would get these as well in all likelihood. There is the possibility of the G-40 40km quad packed missile from Turkey (if they complete development) which could also work) but i dont see enough room in F-22P (if we use Naresuan Class as a template) for more than 12 cells...more likely 8 like Naresuan Class. With that, they absolutely would need a quad packed SAM to make it worthwhile unless they load tye ship up with something like HQ-10 (6 on each type 730 and 24 cell FL-3000N) which still isnt ideal... Although you may be able to fit 16 cells for. Umkhonto in that area (8 cells for the Hamina class with far less space).