I'm in this now.
If you add up lawyer, CPA,
immigration, company, taxes on your "salary", etc. you quickly get to 10-12K. It's definitely one of the more expensive routes, but the company+work-permit allow you to get into business locally if you like and your 200/300K won't be stuck if at any point you decide Panama is not for you afterall. There's no need to hire any Panamanians unless you want to hire foreigners other than yourself.
Disclaimer: I'm from a friendly nation and still in the 2-year provisional phase, so I don't know if this will truly end well. As 3 separate law firms offered me this route I'm fairly confident that it will.