According to the government the duty on "still wine exceeding 5.5% - not exceeding 15% abv" is £297.57 per hectolitre, or it other words, £2.9757 per litre (just above £2.23 per bottle).
72 bottles of 750ml contain 54 litres, so a total of £160.69 just for duty.
It may be different if you are talking about sparkling wine or if the alcohol rate is higher or lower, see the other rates listed on the page linked to above.
But remember you'll also have to pay VAT (on the total of wine + shipping + duty).
Also, the shipping company is likely to charge you for the privilege of having to pay taxes and duties. The amount varies a lot depending on the carrier, from nothing to a few dozen pounds.
On the other hand, you should no longer pay VAT to the supplier.