That's not bad! It was years ago when I remember reading a letter about it and can't say it's at the top of my list to stay uptodate on!
its the monthly rental on the machine that's the problem lowest i can find is £20/month ish for up to 30 letters a day
plus RM offer a pay on-line (up front for credit) and print off on your printer service they charge £5 a month for it but no discount on the postage
i just buy stamps in 20s including large letter its easier to file one receipt than 20
i even pay more i.e a 97p stamp (for foreign letters) for the 96p large letter 100 gm - 250 gm cause its more convenient
i also don't agree with the its packing charge not just postage to justify high PnP if your a mail order company packing is part of the work so should be costed into the products shops don't charge a talking to you about the product fee if you go into the shop to buy but some can help you for hrs. His wages are costed into the annual model and added to the mark up across the product range as an over head same as light and heat rent and rates etc
it does make your products look cheaper to search engines but people will re check once they see an unreasonable PnP to factor in
ATB
Duncan
ps just checked a small jiffyy is 8-10gms
a 9mm ferro is 30gms
so you should just get for 1st class
3 for 66p plus 7p
8 for 96p plus 7p
16 for £1.33 plus 7p
24 for £1.87 plus 7p
or save a bit more and go 2nd class