As others have said, both have their pros and cons. Electric does require less maintenance and you just charge your batt and go. But you can only run for 15-20 mins on a single batt. With nitro you can run until your rx batt dies (1hr+). Electric is harder on the drive train, so it will require more maintenance in that area. Nitro will require tuning (which should be very minimum if you buy a good engine) and clutch maintenance. I have owned both and the one thing that was a big plus for the electric was when practicing: you don't have to worry about flaming out if you crash during a practice run and you are all by yourself. I own a track myself and I used to use my electric when I was going through the process of building a new layout. On the flip side, I personally get bored running electric pretty quick. There is just something about nitro that keeps me going.... One big plus for nitro is the longer mains! With electric, they will only run mains up to 10 or 15 minutes, while with nitro the a main is generally 30 minutes, if not longer!
I would also recommend to look at what classes are big in your local area. Here in MI the electric 1/8th scale class is slowly shrinking and nitro is (finally) slowly growing. You might want to talk to some locals to see what the trend is, so that you won't be surprised that your class is gone locally in 6 months....