There are mobile Auto Locksmiths who can programme the chip in a used key to match the cars ECU. They copy the code from the ECU and use that to re code the key. So, there are lots of Crossfires in the breakers yards. There is a link to one on the UK Crossfires website for a start and lots on ebay. Buy a complete used ignition barrell with keys from breakers. Fit and get a mobile man to re programme the used key. Might take some organising but a cheaper solution.
Additionally, the key man can read the code off a used key, and use that to reprogramme the ECU; ie, the other way round.

Incidentaly, I bought a new original blank off ebay for £35 and it cost £3 to get it cut to match my existing key. It now opens doors and turns ignition on. The dealers tell me they can programme this for £40 by reading the ECU and copying the code to the key.

Good luck

PS - or you could just join the AA and take out key cover. Then ring them and tell them you lost your keys!