You are getting differing answers because the answer is different for every country. In some countries, you arrive at a customs port of entry and are given a ‘permit to proceed’ which allows you to fly internally. Usually in these cases you have to depart from a customs airport.
With crew duty, again it depends on the country of registration of the aircraft. Usually the limitations are less stringent for private flying.
To get a more accurate answer would require knowing more about your intended area of operation and home basing of the aircraft. However, when it comes to ‘owning’ an aircraft, the biggest driver between flying private and commercial is usually tax, both on aircraft purchase and fuel, and therefore how much the principal is prepared to pay for the advantages of private flying.