Given that the lid of the pen is often the most attractive part, and the part one sees first, I'm not sure that obscuring part of it this way with the pen itself is the best composition for a product shot. I am very particular about my pens and tend to pay a bit for them ('though maybe not as much or as often as some), and the clip and lid are critical. I would suggest considering a clear or white lucite block to rest the pen on, so that the whole lid can be shown off to advantage.
Is the 'high key' look what they're after? I can't help thinking that a pen with this much light/silver/white would look much more dramatic against a dark background... That said, the shot itself works.
mamiya makes a very nice manual focus 80mm f/4 macro lens.
its very affordable.
I used to have one when I had my 645 1000s
the only downside is you also have to have the macro spacer that goes with it in order for it to do 1:1. without the spacer its just an 80mm f/4 lens.
It's very common to photo pens posted (the cap attached to the back as if you were going to write). I made a little "holder" out of polymer clay - just a thick disk (like a stubby soda bottle cap), with a recess for the pen. It's not great but it works for now (needs to be leveled). You can see it here.
Edit: For the product photos, maybe a tiny dab of plumber's putty to keep the pen so the clip is on top while the pen is flat on the table?