How much would it cost to pack supermarket groceries for shipping?

The fee to pack groceries into boxes for shipping is chargeable at £7 for the first 25 items. Thereafter, it is £5 per 25 items. There is an additional fee of £0.50/item to pack fragile and liquid-containing goods. 

The fee excludes shipping the cost. Please also see other relevant questions about ordering groceries here.