A.: Good afternoon. I'd like three air mail letters please and I'd like to send this parcel to New Zealand.
PO.: Air mail or surface rate?
A.: Well, I want it to arrive by the middle of October. It's for my nephew's birthday. How long does surface rate take?
PO.: About three months, so it's not going to get there until the end of October.
A.: How much would it be by air?
PO.: Er, £14.80 by air.
A.: And surface rate?
A.: Mm, surface rate then. I'm not going to send it by air. It's too expensive. It doesn't really matter if it's a bit late.
PO.: Okay. Anything else?
A.: Er, yes. I also want two books of first class stamps, and a £10 phone card, please.
PO.: Right. There you are. That's £22.20 altogether, please.