I don't know where the "$30 or $300" conundrum comes from. (disclaimer: my company, Zill.Net, does both shared server and managed server hosting of OpenACS, at $79.95 and $175 per month respectively).
I have customers with decent ecommerce setups, nonprofits that get lots of hits and do bulkmail, and other commercial sites all running OpenACS - none of which go over 10GB of traffic in a month.
The only site I ever had that got close to 10GB was one that got slashdotted, and had a 1MB file for downloading as its main attraction.
If they already have a site, the question is, how much traffic do they get now? It is unlikely that an OpenACS site, even with forums, email sending, etc. would double their current traffic.
