I bought one of these kits and you would be surprised how much of it you do actually use! How many of us have used improvised tools in the past because we don't have the real thing: screwdrivers as drifts or scrapers, or lever bars etc it's much easier with the right tool and your not damaging the improvised item. I genuinely thought I would never need the giant size socket set up to 50mm + unless a passing tractor needed a wheel changing: but then my son bought a Ducati with a 45mm wheel nut! The biggest pleasure in a kit like this is that you can put your hand on the right tool in an instant, without rummaging in a box, it's also easy to see at a glance if they are replaced and nothing is missing. As previously mentioned at around £3 a tool it's good value compared to having to buy each individual set of kit.
You can also get it few hundred £s cheaper if you shop around, I got mine from "HiS Scotland" for a lot less than quoted on here.