Check with US customs on how much your limit is for 5 days... but I mean, to answer your initial question, this is my opinion:
If you buy it there and you get a dead-on-arrival component, you'll be pretty much S-O-L with that part, or it'll probably be more complicated than it needs to be to get a replacement (and the shipping cost won't be negligible). It needs to be a pretty good deal to make it worth your wild, and you gotta factor in the conversion fees that you'll need to put on your credit card (or cash if it's the case) when you buy with a different currency.
So, I wouldn't worry about security (but again, check with your officials), but I would be concerned with warranty, or more-so the shipping costs if you need to send stuff back (cause they most likely won't cover the shipping costs).