Bottom line is what are you tryin to do with it.I feel if you gonna put anything out for consumers whether its an album or mixtape,its worth mastering,cause you are tryin to build a reputation for good music.So what kind of mastering?Witgout all the facts Id say that you may not have distribution,you didnt record on a console with expensive pr-amps,I would just do a software based mastering makin sure all songs are at same level and its boosted without clipping, E.Q.There are alot of people offering mastering and the majority of them may only do as good of job as you(if you have a good ear) and if you had and knew the equipment.Mastering is an art in itself and it can be as simple as you want or complex.My motto would be if you record at home master at home,If I went to a big studio and spent money I would spend extra to get the mastering