Those factors are relevant if the kicking competition is close. The Cardinals have aggressively purged what they saw as overpriced contracts from their roster. Kerry Rhodes and Adrian Wilson were among the higher-profile salary casualties. The decision to release O'Brien Schofield, who was scheduled to earn $1.3 million, showed the team would trim more modest salaries as well.
These are the sorts of value judgments teams make regularly. The Cardinals have a new head coach and new general manager. The new leadership is setting up the salary structure to reflect how it values players. The relatively high salaries for offensive linemen Levi Brown and Daryn Colledge put pressure on them to play well this season, or else.
Feely is scheduled to earn $1.55 million. The deal for Carpenter would save nearly 50 percent in cash and cap, as @Jason_OTC notes. Feely and most other players inherited from the 2012 roster have no equity built up with the new staff. They're vulnerable if the team thinks another player can produce similar or better results at lower cost.
Carpenter does have some equity built up with at least one prominent Cardinals staffer. He made all eight field-goal tries during Todd Bowles' three-game run as the Miami Dolphins' interim coach to end the 2011 season. That eight-kick streak included tries from 40, 44, 44 and 58 yards during a 19-17 victory over the New York Jets to end the season.
Bowles, as the Cardinals' defensive coordinator, isn't going to be making personnel decisions regarding kickers. But the context caught my attention when thinking about how Feely was starting fresh at age 37. The new coaching staff is judging him more based on performance during training camp and preseason games.