Cost of re-tiling roof

My 3 Bed Semi was re-roofed last year at a cost of £4,000

In 1999 I had my two 3 bed hip-roofed semis done together, outskirts of Bristol. I got 3 quotes, one picked from ads came in at £9000, one from man who did a neighbours house at £4500, and the last one from a chap hiding his income from his estranged wife, £2800 cash. These prices were for both houses, not each. I went for the £2800. It was scaffolded, stripped, felted, new flashing, new ridge tiles, new timbers all round under new fascias, soffits & guttering. Ideally it would have benefited from new tiles as the 1930's ones were thinning but I opted to re-use them and only paid extra for second hand replacements for broken ones, another £80. Well satisfied with job, only complaint was a couple of tears in the felt where toes of boots stuck in while refitting tiles. Mike