'Three days to decide or the price goes up'...hmmm, to me this sounds like pressure sales tactics.
If you didn't buy, what's the worst that would happen?
I've also recently been astonished at new fitted kitchen prices, but also at the add-ons and how everything creps ever upwards. it strikes me a lot like wedding planning!
A lot of how you go forward if you decide to show the current company the door, lies in decisions like, have you given them any cash yet / if so can you get it back? If no money has slid their way, then you are in a powerful position and I would not be surprised if giving them the elbow didn't result in a sudden cutting of price.
It also depends on whether you can either employ local joiners, or use your own skills, to replace decent but cheaper cabinets from (say) B&Q (other kitchen unit sellers are available!).
I'm doing the latter and have decided that as we are staying put for the foreseeable, I can get it as we want it, but then again, we have never lived 'photo-shoot' lives. lean and convenient will suit fine, and if I get fed up with it then I'll repaint the cabinets.
I guess whoever buys the house one day will put their own kitchen in. But for £23k I could do a massive amount of other interesting things!