Hey, I'm sitting at home recovering from the same thing....
I had sinus surgery about 5 years ago in New Zealand, and was told I'd need it done several times again in my life, every few years probably.
Then I moved to Vancover (canada) and got operated on just last week. I've been told that if I take care of myself, do all the aftercare, it will be permanent. The only downfall to this is I have to go see my doctor every month or so, so for, anyway, I'm trapped in Vancouver.
The options I was told about for this permanent surgery were being put on a 7 year wait list, going privately in canada (where I have residency but not citizenship - not sure if that makes any difference) for 10 grand CA$ or going to the stated for about 50$.
I got put on some emergency short list and got a surgery date 3 weeks after being scanned... this was because of cf, the mess my sinuses were in, the fact that I have (had, at least..) plans to leave here in a few months, and because there just happened to be an unfilled emergency slot at that time.
Within Canada there's a place in Vancouver and and place in Toronto. My doctor said they're the only places, I'm not sure if he meant locally (w/in north america) or the world.
Depending on where you're based, and what your money situation is like, it could be worth coming to vancouver to get it done once and for all....
let me know if you want to know anything else about this that I might know.