I have looked into making the IRO bracket myself, and if you can get them for that price, go for it.
Short of doing ALL of the cutting and fabrication yourself you will be hard pressed to beat $170.
Since I don't trust my own welding skills, I looked into having a shop laser cut the pattern, then having it welded up. One bracket alone would have cost me about $400 for just the brakcet (not the WJ trilink), or I could have had 5 made for about $1,000. If I went the bulk route, I wasn't sure I could move the 4 extras (even selling at my cost + ship they are still expensive) so I just called it off and decided to wait.
If I could get my hands on the design for the JBA bolt on bracket I would much rather have that made though. Maybe now that JBA exited the liberty market the design might become available (of course I wont get my hopes up, people are pretty protective of these things).