Great reference point for Gutter replacement http://www.wickes.co.uk/pcat/guttering/. There are many outlets for gutter replacement parts. Wicks is a very good source and the prices are quite low. The quality is acceptable and they stock standard sizes of half round and square profile guttering. Sometimes if adapters are needed ebay is another great place to buy. Delivery is often next day so we can get on with the job as soon as possible. Other places to obtain gutter parts are B&Q whose gutters are good quality. Screwfix and tool station are good places to pick up deep flow guttering. Gibbs & Dandy also have a good choice of guttering and other building materials. It is not always necessary to replace a gutter joint. If the rubber seal inside has perished that can be changed. This is a cheaper option but just as effective. We always carry tools to tackle most jobs. One of the best standby's is the good old wire coat hanger. This can be bent to the right shape and can often dislodge material like moss and rotted leaves. Gutter replacement might be a good option to smarten up the outside of a property. This will certainly add to kerb appeal if the property is going to be sold.