I'm going to be travelling tomorrow and looking at a used DDJ-1000. The seller said it's lived on his dresser, never left the house, etc.

Can people let me know what things tend to fail on these units so I know what to look for?

The seller said the only issue is he thinks that the crossfader is off a bit or uncalibrated, but he never used it to mix. He thinks the latest rekordbox with curve adjustment might fix it (he's on an older version), but if not, is it a pain to get it calibrated?

Secondly, I primarily mix techno, decks tracks & loops. I'm not against the idea that someday I might work on scratching for sh*ts and giggles, but in general I don't do it. How worried should I be about a crossfader that's a little off?