I hear lots (even from employees in the electronics depts of some chain stores) about plasma sets having a 3,000-4,000 life span. I'd like to think that, for $6-7,000. (for a 50" set), I could look forward to watching more than just 1,500 movies (less, if I use the set as a monitor for general satellite reception for regular broadcast shows). Are newer sets addrsssing this issue? Should I wait longer before investing?