In your list of parameters you don't mention the number of modules/plugins installed. We're expecting to install some nonstandard plugins: Questionnaire, Feedback, QuizPort, OUwiki, the Course Content bloc and maybe two or three more. Would they have a significant effect on cost, speed and/or the stability of the site? We're thinking of not very expensive hosting around $20 a month. It'll be an experimental site, for teachers wanting to collaborate to share and develop courses so not many users or high traffic, at least not at first. We know about avoiding large multi-media files but we're not sure we're aware of other things that can affect cost/performance. Are we being unrealistic?