If you have over £300 to spend on a new or secondhand bivvy, then the world is your oyster. There are some superb new bivvies in this price bracket from the best brands, such as Nash, Fox and Trakker.
If you have the money, an expensive bivvy is a good investment, as it will keep you and your tackle warm and dry in even the worst weather conditions, enabling you to concentrate on your fishing to the best of your abilities.