The only difference is the buzzers and whistles. Most free ones are a stripped down version, pretty straight forward. The ones you pay for have more options to play with, but I have found that it is something rarely if ever used anyways.

Here is a link to some fairly cheap DVD burners

http://www.newegg.com/Store/Category...-Burners-Media

You probably dont really need lightscribe, but if you want to stay with what you have you can find it here.