read what you just wrote and the you will find the answer

There is a lot of competition out there, so what ever you can do to make yours compete would be a good thing.

It's hard for a lot of people to listen though a mix for what it could be. they want it delivered to them as if it were a finished product and not have to read into it.

If you feel that more people would get what you're trying to sell if it sounded better, then you should do it. If you don't feel that it will bring something to the table, then you shouldn't. If you present something that is competitive and polished, people will take you more seriously, this goes for everything including the packaging.

Only you can decide what is "best" for you.

If you master your own material on the same speakers with the same acoustics that you recorded it on then you may not be hearing what is really there which may lead you to make judgments that are faulty based on what you "think" you are hearing.

Lot of times when clients come to me for mastering they are really hearing their material for the first time outside their studio. It can be a very "ear opening" experience and many are shocked and what they did not hear when listening on their only speaker systems. They suddenly hear things like low frequency traffic noise outside their studio or the sound of the HVAC system running while they were recording. It is not because they were not listening for these noises it was because their acoustics and speakers were not letting them hear them in the correct perspective. There are also the things that an outside person may notice like the trailing end of a song being chopped off prematurely or the panning difference between one take and the next that were spliced together and now the guitarist is on the left when he should have been on the right where he was for most of the song. Things happen in recording that are part of the recording process and as subsequent steps are done they merge into the fabric of the song and it is not until someone else listens to it that these "problems" suddenly emerge.

By taking your mastering to someone else you trust you are getting a trained set of ears listening to your material. Those trained set of ears belong to someone other than a band member or the recording engineer for the project and don't have a memory attached to them. The mastering engineer is only listening to what he or she is presented with and have no knowledge of how it was arrived at. They don't know all the gory details of the recording process and are only focused on what they are hearing from the speakers. If they are good at their profession they are very neutral in their approach to every song and only concentrate what they are hearing and are not concerned with the "band politics" or the individual "needs" that seem to be part of every recording process.

If you feel comfortable doing your own mastering then by all means do it. If you want your stuff to be professionally mastered by a mastering engineer there are a lot of good ones around and some of the best are on this forum. Only you can make that decision.

Best of luck in whichever direction you chose to go. Hope this helps......!