In reply to alexgoodey: There are lots of good boots on the market, but they come in a variety of shapes, many of which will not fit you, though they may fit other people. It is therefore important to try on as many boots as possible in order that you find a pair that is right for you.
Ideally go to a good shop where a boot fitter can give you advice on your foot shape, suggest some models to try and things like Superfeet that can improve the fit. Footwear is something that I wouldn't buy on price, particularly if you are earning a living by being on your feet all day. Boots that are badly fitting will make every day miserable and boots that are cheap may be a false economy in the long run. Good boot brands to consider include:
Aku
Altberg
Asolo
Boreal
La Sportiva
Mammut
Meindl
Salewa
Salomon
Scarpa
Zamberlan