I am the Kat that Walks By Itself

I suppose I could offer free freight and price accordingly.

You mean add the freight cost to the item cost? Would that work if the postage was different to different countries? Or would you add the potentially most expensive postage cost to the price, so as to cover it for everyone?
I think it's also possible to limit where one will post to. Certainly, there are Etsy shops I can't buy from because they only post to the continental US.

but they take a commission

So does Etsy, but it's something like 3.5% I think.

I'm not keen on funding that utter bastard Gareth Morgan whose son runs it.

Then don't. Don't feel like you should give TradeMe a go if you loathe the people associated with it.