I'm not exactly sure what you mean by BOM. Last year, there were two BOMs.
I assume (as Nate did) that you are referring to the BOM for the goal. FIRST released this before kickoff. The link for that is available:
http://web.archive.org/web/200201261...2/earlyBOM.pdf
As you can see, it cost about $250 to build them with the exact same parts. There were three of them on the field, so to build all three, even using thier "cheap" option would run $500. We do not know if FIRST will release a BOM for the field this year, as there hasn't been any announcement, and how much it will cost if they do.
The other BOM is one that teams provided FIRST listing the parts used on the robot. This has been required, in someway or another every year I have been involved, except for 2002. In fact, it was required until part way through the last build period, when FIRST said that it wouldn't be required.