Renovation - Spray foam or Batt Insulation! Advice please!

If that wall is going to be catching the heat, then the higher R value of the sprayed in foam would let you come out ahead because that wall will not heat up as much as fiberglass batts. Since the cost is even, go with the foam if that’s what he recommends as it will also quiet down that portion of the house as foam is about the best damper of sound out there.