I have been thinking about the rowing machine, but short of renting a U-haul for $39.00 and stealing the one in the local gym, it just is not going to happen!
A couple of things that I did not mention:
1. Always check the odds and ends boxes at Home Depot first.
2. Make friends with a construction worker/machinist/carpenter.
3. Go to scrap metal/junk yard. They usually sell you pipe/fitting/etc for pennies on the pound. You should see the four man-hole covers I picked up for $11.50. Had a machine ship drill a 2 1/4 inch hole in each one, and voila, 4 70+ pound plates.