We bought this for our daughter's third birthday and are really pleased with it. Although it's plastic, it's very sturdy and durable. There's lots of bits to it: greeting cards, newspapers, magazines, notepaper, pencil, envelopes, driving licence and other forms, stamps, airmail and photo stickers... I thought this was excellent value.
I do agree that the items are perhaps a little on the small side, but don't feel it's worth losing a star for! It'd be easy to make up your own bits and pieces out of magazine pictures. Think I might photocopy the forms as others suggest, before they are used.
Both our daughter and 5-year-old son enjoy playing with this post office.