They didn't choose Ortiz over pitching, they offered Ortiz arbitration expecting him to decline it, netting them picks. It backfired.
As for the penny-pinching, what did you expect? They just missed the playoffs with a 170+ million team, have been over the luxury tax two years running and there's a huge crop of pitchers in next year's FA market.
Perfect storm for them to try to stay under the luxury cap.