Go for it but as other posters have said do get several quotes - also some estimators have better design ideas than others and can come up with things you haven't thought of.
When we moved in, the kitchen looked terrific but it just did not work, so we went back to basics and had the whole thing replaced (about 17' x 12' with some fiddly bits beside the AGA). The cost was around £12,000 last year.
But, as Alira said, drawers, drawers and more drawers! I can certainly no longer scrabble on the floor to get to the back of a base unit and DEFINITELY no wall units. There undoubtedly some very athletic young oldies but who wants to be teetering on a kick stool when in their eighties when the knees and back have disintegrated?
Also, I really wouldn't advise going away. Whoever does the kitchen and however well planned, there are always snags for which the fitters need an instant decision. Not knowing the layout of your house, it is difficult to tell but there are invariably ways of "making do", otherwise is there a local B & B where you could stay while the work is being done, so that you could get back home each day?
You will love your new kitchen when it is done.