Hi. I suspect that you are being quoted the maximum Avios lowest cash option. There should be an option to select more options which will reduce the number of Avios but increase the cash element.

The return fare in Club World should be 250k plus
£1680 in tfcs for 2 adults

You really would benefit from having a BA Amex companion voucher

I certainly wouldn't be using Avios if that is all you are being quoted .