Years?? I wish I got that out of my strings. The longest I've been able to hold off putting new strings on a fiddle was around 10 months. I have some classical friends that change their strings like clockwork every 4-6 months.
No, the expensive ones tend to be less strident or edgy. I guess it depends on the fiddle though.
I had a hell of a time finally finding a fiddle I could tolerate. For whatever reason, my ears would take any edginess and multiply it. Took me a few years to find something.
I noticed something was wrong when I was practicing with a rental fiddle, and wanted to smash it against the wall. It wasn't a bad fiddle, but my ear was not liking it, but I didn't know why. I just wanted to smash the thing. Luckily I figured out what was going on.