There is a simple piece of arithmetic to apply to the price of a bottle of wine in the UK's heavily taxed market.

In essence, spending a fiver on a bottle of wine makes you a tax contributor more than a wine-buyer.

Spend a little more and the benefits to you in terms of quality drinking increase dramatically. 

However it is also true to say that upgrading from say £15 to £20 makes less of a difference than going from £5 to £10.