We spent under 2k on ours, fitted ourselves. I think it came out very well.
We fitted our 2nd IKEA kitchen after being impressed with the first that we fitted into our old flat. We went for one that wasn't chipboard/mdf doors but instead solid oak (not veneer). The whole lot set us back just a shade over £2k and that's for 6 base units (2 of which are the funky corner units with double carousels) and 9 wall cupboards (there is no large corner cupboard for the wall hung ones, so you use 1 corner unit + 2 30cm cupboards either side). this also included things like the extractor unit and the kitchen sink (which IMHO is nicer than the B&Q ones as you cut the hole for the tap yourself rather than it already having 2 holes, one of which you cover up with a cap). Also in that price was custom made work-top (you specify the exact dimensions you need, including depth, instead of just cutting rolltop down to size) and hiring a router and template for doing the mitre joints myself.
We already had a free-standing cooker that we used instead of a built-in one as the only way to get a double oven completely fitted is to use one of those tall units and have them higher up, which we didn't fancy).
Fitting isn't hard, but is quite time consuming, especially if you work full time, but can be done at weekends if you manage to plan easy attainable targets that still leave the kitchen somewhat usable. You don't need many tools to do it either, a few screwdrivers, a drill with hammer mode and potentially a circular or jigsaw if you need to modify any cabinets (had to modify the extractor cabinet and two of the end ones as they needed to be slightly less deep).
If i'm totally honest - the Dishwasher is one of the things we could have done without in the Kitchen. We use it rarely (once every 2 months) and our old one added about £80 a year to our electric bill when we were using it every 3 days or so.
That and the fact I usually still have to rinse the plates first, It doesn't take some of our plates / knives - & we spend 2 minutes loading it - and 2 minutes unloading it (when we can have the dishes all done & away in 10 minutes anyway - compared to it's quick 30minute cycle) - I just don't see the point.
If you needed to pre-rinse plates then you either had a poor/older model dishwasher or weren't using a decent enough detergent. The plates go into ours with all sorts of muck on them (my mother was agast that I was putting a pan with some burnt on food in without washing it by hand first). Everything comes out sparkling, and uses less energy than doing it to a similar level by hand. It also adds not a lot to our leccy bill, modern dishwashers can use less energy than washing properly by hand (especially as ours is super energy efficient, using cold water filled sides to do a lot of the drying by condensation). We don't use our hot water that much (have showers) and so heating an entire tank of water up just for washing dishes would be more wasteful for us.
Please don't buy anything by Creda, Hotpoint, Indesit or Ariston.
Agreed, Bosch, Siemens, AEG or Miele all the way - it costs more initially but you'll save in the long term. Having said that, our old (8 or 9 years) Indesit washing machine is stubbornly refusing to die (which is a good thing as it's added expense we don't need before going away on holiday!).