Xbox controller stick drift - is my controller dead?

Very recently, the right stick on my Xbox controller - the official MS one that came with the Xbox three and a half years ago - has started drifting when I don't hold it. Not all the time, but often. I've searched for solution, tried the calibration tool on the Xbox, and nothing has fixed it.

Is it safe to assume that it's just time to replace it? I'm not going to open it up and solder anything, so it looks like there's no hope, right?

I guess after three and a half years it's not bad, though I don't play a whole lot on the Xbox. Maybe 500 hour a year (wild guess).

I've looked at other controllers, but everything that's recommended is much more expensive than the official controller, unless I'm missing something.