If you are looking for something cheap (less than 1500 euros/dollars) it might be difficult.
Setting up your company might cost around 900 dollars, including the agency fee, however don't forget that you have to travel to Hong Kong for the setup. As you said euros I assume you live in Europe so, this flight will cost at least 500 euros a very cheap one, but usually they cost around 1000 euros + accommodation.
Is it all? Humm, if you need to open a bank account in hong kong a few banks will accept doing it with 1000 euros/dollars, however it is safer if you have 5k.
I don't really know what kind of business you want to create but︀ if that's all the budget you have, it might be easier doing in your country.︁ Give more info about your idea and we will try to help you.