Here are some pics of my rails/bearings acquired from ebay. I got everything I needed for less than $250 shipped. If ya keep on those auctions you sure can get some good stuff for a steal!
Z axis (3/4" X 18" supported)
Z axis 2
Z axis 3
Y axis (double 1/2" rail x 36")
y axis 2
x axis (3/4" X 24")