Okay, this seems to have started a debate - good
Firstly, I'd agree that the max number of keyword terms is 3-4 per page. Now on to keyword density - a few years ago you used to be able to rank high for competitive keywords if you had a high keyword density, and very few links.
Times have changed and now that is not the case - the keyword you have mentioned, in my eyes doesn't appear to be a competitive keyword, so it's likely that you could rank #2 or #1 if you have used this keyword alot in your content.
Nowadays, it's links that count - BUT one-way anchor text links, not reciprocal links, don't waste your time with them. Ideally, if you have 2 websites get them to link to site A and you link from site B, buy links, write articles, submit to directories, create a blog on another domain.