BPS with Fetal Biometry and Placental Doppler

Good day po! Ask ko lang, ano po bang pinagkaiba ng Biomtery with BPS at BPS with Fetal Biometry and Placental Doppler? 32 weeks and 4 days pregnant po ako. Nung 30 weeks pa lang po ako, ang recommendation ng OB ko is need ko magpa-Biometry with BPS. Then last Aug. 15, Thursday nagpa-checkup ulit ako, need ko na raw magpa-BPS with Fetal Biometry and Placental Doppler before ako bumalik sa August 29. Mas mahal po yung may Placental Doppler and Fetal Biometry sa Biometry with BPS lang. Any advice po please?