Took a few months to be honest, as we were both working full time and doing it on weekends only really.
I took a chance on B&Q carcasses, which were the cheapest on the market by far. They were all precision cut, everything felt high quality. It is all melamine faced particle board regardless of who you buy from, unless you go to an actual carpenter and pay for wooden ones. The doors I got were really high quality for the cost B&Q Stevia which were MDF with a thick plastic gloss coating.
I bought the oak worktops from a supplier on eBay for £300 total.
Bosch washing machine £150 after Bosch rebate deal from PC World open box deals section in store.
Bosch slimline dishwasher £180 from Facebook Marketplace, like new.
IKEA Smaksak pyrolytic oven new in box in bargain corner, presumably a customer cancellation. Haggled it down to £250 from £500.
The thing that saves you money with DIY is that you can go round at your own pace finding all the bits cheap with a bit of shopping around. With a tradesperson they are getting it all out of a catalogue, even with trade discounts.