5c may be the smallest denomination legal tender in currency but fees etc are usually paid via paypal/credit/debit card so rounding in that regards is not what ebay do.  They round to the next whole cent if it is a fraction.  I have queried ebay in regards to this on a few occassions when I have sold 2 items of same value and on one was charged 1cent more in fees - sometimes they round up and sometimes they round down, no real consistency.