I'm not sure what that means. "Cheap" in what way? Her death was depicted as a major thing, a tragic thing. It was important. It had consequences. It hurt other VOY characters. The only way I could conceive of calling a character's death "cheap" is if it has no impact and other characters don't care about it -- but that's clearly not the case with Janeway's death.
The follow-ups handled it very well. The book where it actually happened, Before Dishonor
, was simply not very good, and that's what a lot of people have a problem with.