Define what you want from a patrol frigate first, then we can better assess the dollar value of each hull.
I'm going to start with Convoy Escort, which means able to deal with Oscar-class AShM volleys. 24x P700 missiles. Or these days, Yasen-class, which means 32x P800 or 3M54 Klub missiles. Per single submarine. (once the average merchant ship does 20 knots, that greatly reduces the need to convoy up)
It also means going someplace the natives are restless to show that you are paying attention, say like the Red Sea when the Houthis are having a hissy-fit. Which would mean having enough magazine depth to handle several incoming weapons per day for a week or two.
I fundamentally object to the assertion that these are all utterly detrimental given they are patrol frigates, not frontline surface combatants.
Would you agree that you should be able to send a Patrol Frigate to the Red Sea as an escort to keep the Houthis honest?
That means you need fairly long ranged missiles to be able to guard ships that are between you and the shooter, or at awkward geometries to intercept in general.
It also means enough missile cells to be there for a week or two before you need to leave and reload.
Needing to be able to deal with Yasen-class volleys that are not necessarily targeted at the Patrol Frigate needs 12-16x ESSM (3-4 cells worth of quad-packs)
and 28x+ SM2(equivalent). 32 missile cells
minimum, and 40 or 48 would be better so you could also have ASROCs. Note that there's not a single Tomahawk on this ship right now, and no SM3, SM6, or GPI Glide Breakers for AShBMs or hypersonics, either.
Now we really are up to our
minimum need being 48x Mk41 cells to give you 16x ESSM, 28x SM2, 6x ASROC, and 10x SM3/SM6/GPI.