It's really just a matter of buying it from Amazon themselves, and not another obscure seller just doing business on Amazon. Otherwise, you might as well just take your chances on eBay.
This is what you want to see:
"Ships from and sold by Amazon.com."
You don't want to see this:
"Ships from and sold by JustCalculators."
Changing bands/bracelets isn't really that hard. I looked around on youtube and was able to replace a bracelet with a leather band pretty easily. A watch spring bar tool would be the best way to do it, but I did it with a knife.