Specifically I am talking about this thing:
I am looking for something that doesn't cost $97. I am taking apart a regulator and have discovered that I cannot remove the regulator seat. If you are not familiar with these premium regulators, the seat is a little threaded stainless steel ring that screws into the body. On the top, it has a depression cut into opposite sides that this tool fits into. You cannot just put a big phillips head (or similar) across the ring because there is a valve in the way.
I tried using a pair of needle-nose pliers adjusted such that the tips sat in the little depressions in the seat to try and unscrew it, but it wouldn't budge. So at this point I'd like any suggestions that do not involve a $97 single-purpose tool.