Yes I agree about the 5kg satchel.   In fact I have ONLY ONCE, had someone buy enought to fill a 5kg.   (Actually some Mums buy sizes for years to come for their littlies from me).   The lady with the 5kg satchel had a little boy under 12months, and was buying up to size 3.  Another has 3 children under 6.

I quote for individual items to start with, ... then when I'm asked to combine postage, ... I quote them for 500g or 3kg satchel.   If, on that very odd occasion, they reach 5kgs .....  I still charge the same as the 3kg (in fact, it's only a few dollars more).

As I say, this works for me  .... we all have our little systems.    I have several 'followers' who buy over a few weeks .... and, as I said before, I have an arrangement that I send their invoice (minus postage) every 3 weeks until they finish.   Then they contact me and ask for their invoice with postage.   Fingers crossed, they are great buyers and very honest and reliable 🙂

I sell at a price to cover my costs plus a small profit and sell 40 free per month, and always use the free listing promotions..... approximately 50% sell for more at auction, so I'm happy.

Let's all hope the free listings keep coming and sales keep on improving