Is 500mb Phone Data enough?

Hi, i’m kind of new to this whole smartphone thing and need some help.

So I want to buy a Galaxy S3, however I can’t decide to go with 100 more minutes to make it a total of 400 minutes (which I probably won’t use at the moment as the majority of people my age – 17 year olds text) or 750mb data (250mb more).

I’m mostly going to be using things like skype, youtube, facebook and general web browsing etc. Will 500mb be enough for a 17 year old teenager? I won’t say i’ll be using the phone hardcore 24/7 but definitely more than the average person.

Thanks for the help in advance!