I'd consider signing him on a 1-year minimum, or maybe on a 2 or 3-year deal with non-guaranteed out years for part of the MLE at a little more, but I don't think he's worth much more than that.
Centers are going to have a really hard time finding money in free agency this season. Between the lack cap space across the league, the number of teams already with tons of money/bad money tied up in Center contracts, and the large number of quality big men coming into the league in the 2018 draft I think some of the lesser free agents are going to get squeezed big time.
Brook Lopez, Baynes, Noel, Okafor, Alex Len, and Greg Monroe are all going to be UFA's looking for a piece of the same small pile of money this summer. And that's before teams start cutting non-guaranteed guys, team/player options don't get exercised, etc. Buyers market this year.