bsprague wrote:
Spend your money on a "table top studio" with good lighting. With a camera like you have, I would bet you can get close and crop for the pen. The result should be more than good enough for online photos.
If on the other hand, you are looking for "reasons" to get some more gear, this is a good one. Any "macro" lens from Canon, Tamron, Sigma, etc that fits your camera will work.