I buy them from Cool Effect. I try to pick energy projects because it’s easier to see the accounting ... and you get carbon sequestration faster (trees take a long time to grow vs erecting a wind turbine).
By my estimate, Cool Effect spends around 3-4x of the actual credit costs on marketing related expenses. This is publicly available through their 990 filing.
https://990s.foundationcenter.org/990_pdf_archive/475/475068...
I inquired from credit wholesalers about large volume pricing and found that the actual cost is less than $3/ton of CO2e. For an average US consumer with a 20 ton carbon footprint, that would come out to $60/year or $5/mo if sold at cost. To me this is a no-brainer for anyone that wants to be carbon neutral immediately.
I'm setting up a carbon credit buying club where we can get them at wholesale prices. My goal is to sell them right at cost in a radically transparent way where members provide all the marketing we need. If anyone here is interested in joining, you can email me at paul@carbonspace.com.
CoolEffect seems do be doing a nice job of both marketing and explaining and verifying their projects. I have no problem paying a premium for that. (remember this thread started as surprise that it could be SO CHEAP)