Just pay the duty - it's based on quantity rather than value of the wine.

I brought 6 x 6-bottle cases back from my vinyard in Argentina, went through the red channel and the lady was quite happy I had declared that she charged duty based on 10-15 litres, which was about £19. If it's on a sliding scale basis, expect to pay around £50 for your lot. It's not that much, especially in the context of valuable wines.