If you are buying for the client and not stocking inventory, list the expense account several times with the amount per client and make it billable or not. Let's face it if you and two friends split a 10.00 food bill, someone is going to pay one penny more.

if you use items, enter the qty and the total cost, QB will do the per item rate out to 5 decimals for cost, but money at least in the US and the UK, is held to two decimal places