I will be travelling to BKK with my family, 4 adults + 1 kid (10 years old).

I can use the Fast Track Facility that provided by my credit card. However, I just found out that I can only bring 1 guest for free. Any additional guest will be a charge of USD55/person.

I still have a few fast track card given by the airlines that I did use.

Also I hold a ABTC card.

Question:
1. Can I still use the old Fast Track card given to me by CX?
2. If not, or if I do not have enough card, is it worth to pay for Fast Track Service? I will be arriving around 2pm (TG 404)