As we Know *4 are Basically Websites which are very good and have high traffic from Before, So u'll have to do Less work in it.

Wheras if u are buying *3 then u may need to put in Some extra effort and Time to get More Traffic in the site. So Basically what i Think is go for *3 and make it a Better website than what it is Now.U'll enjoy doing it rather than Just Navigating a *4 Site.