Slate roof repair

1) to replace lead valley at back kitchen extension 2) to replace timber where required on back extension 3) to remove and replace areas of slate at back. Valley 4) to remove all loose render around chimney area To re wrangle lead. 5)To supply and install corner beads and bell cast beads to chimney area and apply a Roughcast render with matching granite chip. 6)to replace sarking board where required at front of property. To supply and install one roll of 300 Code 5 down valley at front 6) to clean out gutterings at front and back of house and remove all waste 7) to remove Roughcast from section at back of house at extension 8) to remove down pipe at back or property and replace with upvc down pipe I was quoted 5,800 for all of the above work - is this reasonable ?