I would definitely do this myself. Are you talking about the shaft seal between the motor and pump end, or the gasket between the strainer basket and the pump? Both are very easy repairs that can be done with some basic hand tools and an hour or less of your time. Check the owners manual for your pump, some have instructions on how to do this, and there are also some threads on this forum about this. Good Luck!
Here's how I look at stuff like this: Give it a shot; if you are unable to get it done, you're pretty much in the same boat you were in when you started. If you are able to do it, then you just saved a good chunk of money. Pumps are pretty basic, and if you pay attention and take your time, there really isn't any reason why you can't do it.
The only question I have would it be the gasket or the seal with the ceramic seat. It leaks around the seal plate and the motor. Also would these seals and gaskets be avail. at the local pool stores or must it be ordered online?
One more question could this do damage to the motor if I did not replace it right away, I mean if it needs to be ordered could it wait a week or two?