This cost analysis is from buying stone and sand by the tri-axle dump truck load and cement by the 94# bag from a lumber yard.
The Rubbermaid Drawer Organizer is available on the internet for less than the Walmat price of $2.10 each, but I have used the Walmart price for this analysis.
The single cost that can make or break the budget is the rebar source. We went to Menard's Lumber and found a large quantity of rebar in the bargin area. We bought enough #3 and #4 rebar to make 500 ties. We offered them $20.00 for it and they were happy to get rid of it. It had been accidently bent when it was unload from the truck and no one would buy it. But since we cut it into 14" pieces the bent pieces were simply hit with a sledge hammer and straighten out and used. So we only had 4 cents in the rebar for each tie. New rebar from a steel supplier will cost 35-40 cents per tie. So finding a source for used or surplus rebar is a good idea. Contractors offen have surplus rebar laying around jobsite near completion of a project. They most often over order to make sure job progress is not halted due to a rebar mistake. Most of them are more than happy to get rid of it. It won't hurt to ask and the savings can be great.
We buy the inserts 10,000 at a time to get the best price. Each batch of 270 ties takes 1080 inserts.
The cost after making 1000 ties is as follows, per tie:
The cost per tie will go down the more the forms are used.
These cost will vary, remember it will the rebar that makes the cost really go up.