Now this is probably small sample sizish, but last year I played Garko exclusively at 2b, and he turned in his worst offense campaign. This season I'm playing Price, and he is batting much worse than last year, when I played him at 3B. This year I'm playing Garko in LF.

Granted Garko's offensive number this year have been on fire the last 10 games, and before that he was batting just as bad as last year (Price has been the exact same way, both started out terribly, Price worse than Garko, but Garko has recovered more). 

Has anyone noticed that playing different positions affects offensive production?

 Hardball Dynasty – Fantasy Baseball Sim Games - Player Profile: Fred Price

 Hardball Dynasty – Fantasy Baseball Sim Games - Player Profile: Ryan Garko

There is no correlation between defensive position played and offensive performance.

I agree with what Tec is saying, there is a clear correlation in your two listed players stats while playing 2b, but it is very unlikely that playing 2b is the cause. 

I did a very quick look over my teams and found nothing that looks out of the ordinary.