Second/Replacement Key Options?

[Workhorse]

Hello all,

One of the items on my list of things to sort is a second key for my 2004 CDTi 75. I currently have just the one key with remote locking and so I'm nervous of losing or damaging it, and I'd be after an identical replacement with remote locking.

I'd be very reluctant to do anything which involves sending the original key off anywhere, so what are my options and what sort of costs might I be looking at?

Thanks all