USPS is better than UPS, DHL, etc. for customs TRUST ME. I am Canadian but I know how they all work having had packages fly from all of them lol. Their customer service and speed is bad, sure but for international orders I'd rather go with national companies and avoid custom fees when I can. You are almost 100% guaranteed to have custom fees if they were bought from a retailer regardless of who's shipping it because they don't give a damn about your taxes and fees unless you communicate the fact that you want to avoid custom fees lol. The only times I was told I was able to avoid custom fees was with retailers shipping with national post companies and the only way to do this is to communicate this with the retailer. I was always charged fees with DHL, UPS, etc. (maybe because they get incentives from their declarations or something).
Anyway, I forgot to try to negotiate the custom declaration with J-Made, the japanese companies I bought my SZ2K. So when I asked they replied:
"Dear Regis-san,
Hello,
Thank you for your inquiry.
We wrote it as 24,000 yen in an invoice.
¥2400 is about $210. (US$) It differs by an exchange rate.
Item is $241.62, but we wrote cheaply as possible.
Please refer to it.
I hope my English expressions aren't rude.
Thank you very much.
Best regards,
J-Made "
The problem with this response is that in Canada, they slap provincial taxes and duties as soon as the shipment exceeds $200 which would have been avoided if he classified it as a gift or under $200 but it's my fault for not having tried to negotiate. Just be aware of the conditions in your country, try to work something out with the retailer and you're golden. I can't do any of this if they shipments are from other companies though but even then if they send it with Japan Post (like they did in my case), they will hand it to the your country's national post service by default.
I paid 40 Canadian dollars in fees by the way.