Despite popular belief, most players aren't just happy to sit there an win nothing whilst picking up their paycheck. Sure there are some that are but generally a good player will want to pick up trophies in his career.
If you don't offer a chance of success money will only get you so far.
We don't just lose our best players because of money, we lose them because we're happy with 4th place and aren't too bothered about success, they may well get a pay rise as well but that's not the main reason in most cases.