we refitted our small kitchen so saved on labour. cost £2500.
did the work ourselves so saved a lot of money.
kept the kitchen sink and changed everything else.
bought carcasses and doors and handles from b and q and other things from all sorts of different shops.
if you are happy with the carcasses then maybe best just to chnage the doors and handles and it will feel like a new kitchen but if the carcasses are dirty or old or something wrong then change those too.
our work tops were a few hundred pounds too. deep and heavy so cost more than we expected but you can get lighter and cheaper ones.