(Edit: Disclaimer; Not aimed at anyone in particular in a hindsight-kind-of-way. Just a train of though that got set off)
It can be amusing to sit somewhere between China and the US and see all the US rants against China. I order stuff from China. I order stuff from the US. Quite often the end result is the same. It's pure luck of the draw which package gets here first. I'd say 9-14 days is the norm, tho. Batteries may not make it; some simply refuse to ship batteries out of the US. Biggest difference is shipping costs. From China? Usually free or a dollar or two. From the US, I'm happy if I get away with $10. Still less than domestic shipping in Norway
Not to mention USPS may well take over a week getting a package out of the country. Coupled with the fact that not nearly all shops send within a reasonable amount of time.
It's just the wonderful world of online shopping. Gives access to goods from all over the world, but may cost you a gray hair or two if you allow it to.