we have a 3 walled u-shaped kitchen and have just bought an ikea kitchen for about £1500. we are getting it installed by a builder and have bought tiles - the total will be about £2500 (but it's a very small room).
The fitting is always what makes it expensive -you can pay the price of your kitchen again - we just have and we used our own fitter. Altogether with plastering, electrics and complete fitting we've paid about £2500 I think (or a bit more).
DH had a week off work to do it when I started my maternity leave. You wouldn't believe the mess and chaos. 4 weeks later when it was useable but not finished I made them down tools, as I didn't want dd arriving in all the chaos. I kept demanding to know when they were going to have it finished and kept storming out of the back door exclaiming "I'm having a baby in case you hadn't noticed"! I'm sure they were rolling their eyes behind my back.