I've done many revenue projections for investors in my startups. As long as you have a methodology and rationalization for your projections you will be fine. So pick the more conservative number, assume a 5% market penetration, and explain what the numbers will look like.

1. The threshold question here is what business goals are you trying to accomplish with this web based project, what is your budget, what human resources you have and what your deadline is. 2. Assuming your budget is $0 to $1000 and you are looking to do e-commerce, I would recommend a solution like www.wix.com because the cost is minimal, the technical knowledge required is minimal and time spent is minimal. 3. If your budget is $1000-$5000, I would recommend using a combination of Wordpress and a theme from www.themeforest.net 4. If your budget is $5000-$25,000, I would recommend either Shopify or Magento Community. 5. If your budget is $25,000+ and you have programming resources and more than 6 months to complete your project I would need to ask you lots of additional questions to give you a more complete answer.