Should we stay in the States or move to Australia?

Okay, so my wife and my oldest child (who's 4), were born in Australia, where My youngest child (who's 2) and I were born in the States. Every 3 months or so, we take 2 weeks off and go back to Australia, so the kids can get a taste of both countries. We spend about $3,400 every time, averaging about $13,600 a year. We've been doing this for about 6 years now (we've been married for 6 years). So, what do you think? Should we stay in the States and just keep doing this, or just move to Australia. Stopping this is no option, because my wife's family is over there and she doesn't want to deprive the kids of getting to know them and deprive my oldest of his home country's lifestyle. Any advice? Thanks for answering!