No doubt turbos can be more labor to install. Cost is roughly a third more than, say, a good centrifugal unit (all but the PowerCharger/ATI sc's will require taping oil out of the pan, just like turbos). Power is about double, and lots of the extra cost are for things like tubular k members, headers, and coil overs, which have a value in and of themselves. Custom fabbing is pretty much a thing of the past - modern kits have all the pieces, its mainly a bolt on affair, though lots MORE bolts than the typical supercharger. You might check out www.modularpowerhouse.com
. They list a very complete Twin Turbo install at $9300. A similar VorTech install (with intercooler, headers, tubular K member, tubular A members, etc.) would run about $6400. A 2.2 Kenne Bell will set you back about $7200 installed with comparable parts list.