You'll need to do some market research on your area and the potential for passengers to see if you have an income source.
AOC you can buy but yes, it will cost a fair bit and you'll need the relevant experience and repore with CASA.
Not to mention airport usage agreement, cost of running the machine etc, all good fun to try and work it out.
That being said there are plenty that have already done it successfuly and plenty more that didn't.