It would be worthwhile for the lite user. Someone that only downloads emails and some webpages. 500mb includes all traffic usage on the internet connection, up and down.
If you only check email and a few webpages a month yes. But if you want to download a bit aswell go for the 1gb package with unlimited 64k after the 1gb cap.
I would say try it and if you feel that its not enough, you can always upgrade to a better package. At 1Mps i would say its not enough. There is so much more one explores once the speeds are good