if you send by recorded delivery you are more easily covered for getting your cost of goods back. as my letter from RM said they cannot confirm postage but could see no problems on route during the posting of the item's time frame. my luck though i forgot to put a photo copy of my invoice in from buying the goods from the wholesaler so i got no cash just stamps! could have got a further £11.25 back by the sounds of it.
On another good point i have just hit my 100th feedback with 100% and 5.0 dsr's over 63 ratings and a 4.9 on postage/dispatch time for 10 ratings. (I think that came from someone disappointed that i went to bed at 1am and they made an order at 9am and received there code at 11 am when i got up

can't please everyone 100% though i suppose.