Some of my listings have ended up being 2nd Class, others 2nd Class large letter, you are spiting them and taking the extra fees.

And regardless the orders will all be going in one box, doesn't matter what the buyer picks, who wants their orders turning up separately by different services? If it's a large letter the listing says 2nd class, if a parcel listing says Tracked 48, if someone buys one of each it goes as a parcel tracked 48 and they get combined postage. I don't understand what you are talking about really.

Any anyway what does that have to do with you taking the fixed ordres fees more than once for the order?