I sent a private response to Roma, which was a more wordy version of the following points. - LISTSERV is a distributed system, figuring out the "complete" resources used to support a list would be extraordinarily complex. Thankfully, it's also completely unneccesary. :) - Any model that estimates a well defined subset of the total resources will probably be acceptable. - One reasonable model is to estimate the local resources that will be dedicated to the list (both machine and human). - Since they site in question doesn't charge for machine resources, use some rates derived from a sample of other people's rates. I wanted to post this to let people know why Roma might ask you for your chargeback rates. :) -jj