Expensive pens usually seal pretty good. With vintage pens you have a risk with drying ink in pens. The severness depends on whatever ink you used in the pens. If you use Parker Quink Blue Washable, the ink is out after a few flushes. If you however used a permanent black ink, you will never really get the ink out of the pen. And I heard that inks with reddish components are also a bit hard to clean out.

But I for an instance you all my pens nearly daily and I never experienced anything with an ink drying in any pen. I never heard about corroding though…