The organization pairs won't be exactly 1-to-1 because building is harder than destroying, different organizations are more efficient and money is non-linear. I

The organization pairs won't be exactly 1-to-1 because building is harder than destroying, different organizations are more efficient and money is non-linear. If you had a "dump oil in national parks" and a "clean up oil dumped in national parks", you'd need $1000 for every $1 of effort dumping oil. So at best this system is a discovery mechanism for comparatively valuing organizations, but it's not really set up that way because there's a big difference between an Antidollar™ donated to cancel out a dollar and a dollar donated after you've reached 0 dollars difference from the counter party.