The one this i will say about Excalibur is their customer service, i have had to use it, as well as a friend, his was an old version (some putz dry fired it) and they sent replacement limbs no charge, i had a scope that fogged up, quick and easy replacement by them.
Since you're just starting out with it, I'd suggest the Carbon Express Piledriver 390.
Midway USA has the whole package on sale for just $219.
I bought one, and honestly can't find anything wrong with it! Great trigger, fast, accurate. I upgraded the scope, but that's only because I had a better one already; the one that comes with it is serviceable.
If, after a season or two, you find you like crossbows, then maybe look to invest in a TenPoint or Excalibur or Scorpyd or some other high-dollar bow.