Actually, it wasnt that bad. The setup uses all the stock piping and the filter is attached directly to the MAF pipe. The filter itself is ~$40 on eBay, but the heat shield cost a pretty penny
But, taken into consideration that it was a one-off custom job which they had to take time to design, the price was actually very reasonable. It would probably cheaper now since they could just copy my design.
PM me if you want to know more details about cost