Before you start importing -- and I mean, before you even buy samples – you should do some basic research about import rules in your own country.
The responsibility is on you to find out this information, not on your Chinese supplier: even if they want to help you it's unlikely that they can give you authoritative facts about such a complex topic, especially when such rules in China are usually different anyway.
However, if you have good communications with your supplier, it may be worth asking if they have ever had customers buying the same goods from them to import to the same country as you.
It's possible they can give you some anecdotal information that will help your planning. But anecdotal information is not hard fact so please start by finding out the official importing and tax information directly from the government agency source:
Your Official Customs Website
Australian Customs Service
Secretaria da Receita Federal
Canada Border Services Agency (CBSA)
Site internet de la Douane
Central Board of Excise and Customshttp://www.cbec.gov.in/
Agenzia delle Dogane
New Zealand Customs Service
HM Revenue and Customshttp://www.hmrc.gov.uk/
US Customs and Border Protection – Importing Information :
European Union (all)
Some general (and quite complex) legal / taxation rules are noted in this website:
Some of those websites are atrocious examples of web programming so good luck getting information for your country! ;)
If your country is not listed here, please visit BuyUSA.gov by clicking this link and use the menu called "Find Export Information by Country"
Sources of import tax information: