Arrowhead knows his stuff, so I am not about to try to discount his advice here. Having said that, I am/was a crossbow newbie, and bought a Parker Bushwacker six weeks ago. I have shot it with field tips and broadheads, and am extremely satisfied with it. It is in the "bargain basement" price range, but has Parker's warranty, so I felt like it was a good way to get my feet wet in the world of crossbows. I have never shot any other crossbow, so perhaps I'd be less satisfied if I had shot some of the higher-priced models before buying, I don't know. When I assembled it the first time, the main attachment screw was too long. I emailed Parker, and received the correct screw in the mail in 3 days, without having shown any proof of purchase, mailing a warranty card, or jumping through any other hoops.
To be honest, the main reason I bought a low-priced crossbow was because I wasn't sure I would like hunting with it, or if my kids would take to shooting it, and I didn't want to be selling a $1000 xbow at a big loss come summer 2011. Turns out that my kids shoot it very well(ages 6 to 11), and like to shoot it. Several of my friends who were also crossbow virgins have shot it, and agree that it is fun and addicting to shoot. In a few weeks, I'll find out whether I like hunting with it, but after a back yard test run with the climber and the crossbow, I don't see a problem so far.
I'm sure there are some reasons for the higher prices on the other models, but I hope no one points them out to me just yet; I'm having too much fun with the cheapy that I bought!