If you're trying to pass custom, you should really provide all the information to the best of your ability, legal and legit. You can classified your item as anything, go with merchandise. Then add a description of what is it, computer part, graphic card. Don't mess with those guys, the worst thing is to have your package witheld or lost. I would consider buying insurance. Tracking number is a must!
If it's okay to ask another question, do I have to pay for shipping to and from XFX? I get how to pay for shipping to XFX, but if I have to pay for it when it comes back to be I don't know how to, and would appreciate help on that.