That's a pretty good deal.
Do they offer cPanel and Fantastico with that deal?
The 500GB of bandwidth sounds like they are overselling. Anyone can offer bandwidth. I could offer 500000000 GB of bandwidth, but I refuse to oversell. Most people don't even come close to bandwidth or space limits. That is why host companies can oversell.
Just do a search on google about host providers overselling, or read this
article.