Oh, not to mention cost of professional assembly $??.??
(and yes I would consider it professional as I have been racing, and building kits since about 1988 so I have a lot of experience, not to mention I run and own my own Car Stereo shop and know how to build, fabricate, weld, and as another hobby of mine is woodworking - how does that relate you ask? - well like this: it takes skill, ability to measure, craftsmanship, pride in your work, and attention to detail!)