I imagine you would sorely miss having an immune function (and blood) if you replaced them all. Bone marrow is where both red and white blood cells are made.
Forged Titanium Parts & Components
The price of commercially pure titanium (CP) has risen sharply since 2003 to 2014, from $15.00 per lb to $30.00 per lb. It is an extremely light weight and high strength material.
Titanium Forgings - Forged Titanium - Commercially Pure Alloys ...