I don't know how much those Irbis bumpers are for sure. Seems like I remember a price around $700-$800.
I'm working on build one of my own. I can get it done with some pretty inexpensive angle iron and plate steel. It won't be exactly the same but something close.
We just received the new crossmember prototype in over the weekend.
These new crossmembers will bolt on to your current 96-02 4runner. All you need to do is trim off the front flat original mounting piece on the front of the frame. This can be done with an angle grinder, sawzall, or die grinder easily. No welding is required at all anymore with our bumpers.