Patternpimp
Marksman
2X4X12" 360 Brass is $294.65 on Mcmaster Carr website. Everything else was purchased; figure out where the cost is in the yellow boy.
WOW, 3 pages and not a single person has addressed the original question. 18-20k seems steep to me also, im not sure how much a block of copper like that would have costed but... I'd assume thats where most of the money went into. The rest looked easy to take care of since they had the tools needed. Not sure how much they would have added for the tool usage