Looking for replacement credit cards recommendation - is it worth getting an expensive annual fee card to earn points?

We currently have 3 credit cards:
-Virgin High Flyer with extra card (the cheaper one) Velocity Points - This is our everyday credit card. We save points and use them for interstate travel. But we have not used the $120 (approx) refund more than once in many years. We currently have about 29,000 Velocity Points.
-Bankwest Platinum Mastercard - $0 annual fee, only use occasionally overseas because zero international transaction fees - happy to replace this if a new card has the same no int trans fees.
-Amex Velocity Escape - $0 annual fee, only use at the supermarket and department stores

We are considering taking a return flight from Brisbane Australia to Tel Aviv Israel from early March for four weeks, and are considering if we should replace all our cards with a new arrangement e.g. one of the deals with 100,000 sign up bonus points. I’ve checked and those flights cost from $2600-$3000 and we would be buying two of those tickets.

Qn - So would it be worth getting an expensive annual fee card ($400) i.e. would we still save money using their points? (Neither the qantas nor velocity points calculator brings up any flights)
Qn - If it is worth it, would you recommend a Qantas or Velocity Points card? We are with Velocity, but it doesn’t matter to me if Qantas gets a better result for that trip.
Qn - Also, if you pay for a flight using an Amex card do you incur a surcharge thereby undermining any savings?

Thanks so much,

this site cannot give individual financial advice including what card is best

as for your last question, under new regulations, merchants cannot charge a higher surcharge for amex.

1 point to add is: You already have an Amex card hence would not qualify for most Amex issued card sign up bonus as they require you to not have held or hold an Amex issued card in the past 18 months to be eligible.