I do identify some of the sales and some, I do not, and simply put mixed used or unchecked, it all really depends on how much time I have at the time I list the sale at hand. Of course I combine sales, all you need to do is ask and it will be done.
For one and all. Based on one letter which is 0.5cms wide and weighs no more than 100g. Stationary charges are always needed too and my prices vary from 10p - 50p depending on the size of the letter needed for the sale/s.