Larry,
I got them from a place called National Pad & Paper. They are located on Thompson road between Carrier Circle and James Street, across from the NYNEX building. No sign out front. The office is located way around the back of an industrial warehouse. The stuff is picked up, or can be looked at, at a loading door facing Thompson road. This guy specializes in all kinds of used stuff including fork lifts, man lifts, mobile ladders, etc. His inventory is constantly changing.
The 10' high by 48"deep uprights were $60 each. He has different heights and depths.
The 99" cross bars were $16 each, 2 are needed for each shelf. I could have gotten 96" or 102" for the same price. At the time I was there I wasn't sure I could fit the 102". As it turns out I could have gotten the 108" and still been alright. I think the 108" were more money.
I added by own 2x4s and 3/4" plywood to make the shelf. He had wire decking but I wanted a solid shelf and I think the wood was cheaper in the long run.
Jeff