Evans is a good defender, but we definitely have more pressing needs (even considering the low price) and we already have too many CB/CB-candidates as it is. We're already looking at Alderweireld, who is a much better defender & much better on the ball, so getting Evans would be rather redundant. Plumping for Evans instead of Alderweireld would be Arsene-esque, going cheap for a decent ball-playing defender when the team is screaming for a top class player.
Evans would be much better off playing for a non-top 5 team, like Arsenal. I'm a bit surprised he hasn't been linked to them, as I can see him getting them back into the CL picture. I can understand the City rumors, but he'd basically be Stones backup, who is already 4th in the City CB hierarchy.