most of that $100 is probably labor. brake lines can be had for pretty cheap, maybe $20? the rest is bleeding it. bleed kit, can be had for around $20. and it's not hard, at all. plus, it's only mineral oil, so it's ok to screw up. hose isn't normally a perishable item. it's usually the mineral oil, which is also pretty cheap. if I were to choose between disc or hydraulic, I'd probably pick bb7's. but this deal came up, and it was too good to pass up.