The type should be free (I'm basing this on the ability to convert military currency into FAA certificates through your local FSDO, although I haven't looked at that reg since about mid-1999).
Having a type is beneficial when it comes to certain future qualifications - first off it is an irrefutable thing on your record for any future instructor/examiner (as opposed to military flight records which you probably don't carry around to a checkride). Second, having a type rating allows you to complete training towards another type rating without having to complete a 15% ride in the actual aircraft if you use a simulator for your training/checkride.