Trying to calculate - roughly - what is the true price of my ticket. Google Flights (separate tickets) is coming up with $22,037, but when plugging the same itinerary into Matrix, I come up with $31,500. Why the discrepancy? What is the cheapest this exact itinerary can be booked for?

2 notes:
- I would never, EVER pay the cash rate for this flight, looking to put the actual paid price on these F/J tickets, even though I would fly this happily in Y (well, maybe Y+), so not looking for a philosophical, "intrinsic value" discussion/debate
- These awards were booked separately, not sure how that plays into calculation.
> JFK-HKG (via NRT) - AA F award
> HKG-DPS (via SIN) - SQ F award with paid stopover
> DPS-JFK (via HKG) - AA J award