300-600
I got one of these. There was a really friendly sounding Post-It note on the front, upon reading it you'd be forgiven for thinking that the person responsible and I were lifelong friends. But it wasn't signed, and there was no indication of how he/she got my name, and the address on the envelope certainly wasn't the official unit address, more like "Control Tower, Heathrow Airport, London."
Therefore straight in the bin.
Gonzo.