As part of our sustainability efforts, we agreed to store and re-sell concrete railroad ties that were being discarded by a local rail road company. The ties are 7.5" x 7.5" x 8', and have rebar embedded. They are just $0.50 / each.
We have 350 square feet of 1x4 pine flooring in variety of lengths (8', 10' 12') available for $1.01/ square foot - a 50% discount. It's cut with a square edge, heavy blue stain throughout, with a 3" face.