I'm going to take a look at a used Fender Blues Jr III, the seller says it's a year old.

Basically, what are some things that I should watch out for? Any tell-tale signs of irreparable or expensive damage?

Thanks in advance guys
Most expensive damage will stop the thing working altogether.
Scratchy pots can be a pita because you have to use Fender parts really for the mounting lugs and they are about $10 each. The board has to come out to replace them though so add a good $50 plus in labour if you can't do it yourself.
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