That $3 shift cable from the hardware store actually fixed my rear derailleur
My rear shifting was skipping for about two weeks and I figured I needed a whole new derailleur or at least a $40 tune at the shop. On a whim I grabbed a $3 shift cable from Ace Hardware down the street because mine looked frayed near the clamp bolt. I almost didn't bother, figured cheap cable would stretch and I'd be back to square one in a week. But I watched a 12 minute video, cut the cable with my $8 Park Tool cutter, set the barrel adjuster to the middle, and reindexed the whole thing on the stand. Took me 40 minutes because I kept second guessing the cable tension at the shifter. Shifts are crisp now, all 9 gears, no skipping even under load on my Tuesday hill loop. Six rides in and it hasn't slipped once. Guess the fancy cable brands aren't always worth it for a commuter bike. Anyone run the cheap stuff long term and have it hold up, or am I setting myself up for a redo in a month?