The guy you have is not always the guy who makes the most sense to throw money at. Guys coming out of team control don't usually give much of a home town discount. It's almost the opposite. They want more money to sign an extension than they'd likely get in free agency.
Flipping a year of Turner for some prospects, and then putting money on possibly a better valued short stop would be a pretty shrewd move if you look at it without any emotional ties.
I assume the team is pretty high on Cluff though after the AFL season he's had. I assume the plan is to stick with Escobar until Cluff is ready, perhaps later in the year.