$16 is a terrible price. Box those up and ship to....

The price alone is less than you'd pay for that relief nib.
If the nib is stuck, and a long soak in luke warm water doesn't do it, either use a hair dryer or heat gun (on a low setting) pointed at the inside of the section, or, dip it quickly in some hot water. Now, I know, some people are going to think you're going to run into a problem with the hard rubber section and hot water, but I'm talking about a real quick 3-5 second dip, just to dissolve some of the caked on ink in the threads. Then it should come out easily.
For added grip, I use a section of old bicycle inner tube and wrap it around the nib while twisting.
Good luck!
Brian