I sympathise, I had a similiar situ very recently. request total, you reply will respond shortly, (you can't always do the combining etc on an iphone) then pays anyway. 

and then there was the one who bought 13 items, and I had to do 13 unpaid items disputes. and then I needed 13 more listings to relist - there goes my 40 free and missed the buyers I could have had in the waiting to pay/ dispute period.  As you say its a time thing too.  we all have a life.