Erratic wear is almost always cause for a rebuild, they may not be floating calipers but if all 4 pistons are moving ok the pressure should be nice and even.
At the prices given, I'd probably go with just getting an already rebuilt or new caliper. I remember snagging a rebuild kit with pistons for $60 or so about 5 years ago, which made rebuilding yourself a good deal, but since the prices are now double..... there's no point to it.
My oil line fix
My 100k stopped odometer fix
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.