Many bikes in this price range have similar frames and components. The components won't last as long as on a better bike, but will be good enough to get you started.
After that you pretty much get what you pay for in improved components. Its like buying a computer - the more you spend the better components you get but the higher you go, the less gain you are likely to notice (unless you are really pushing limits).
If you are keener to commit and spend a bit more trail centres should be able to rent you a trail bike.
http://www.eriksbikeshop.com/Specialized-2014-Hardrock-Base-...
Many bikes in this price range have similar frames and components. The components won't last as long as on a better bike, but will be good enough to get you started. After that you pretty much get what you pay for in improved components. Its like buying a computer - the more you spend the better components you get but the higher you go, the less gain you are likely to notice (unless you are really pushing limits).
If you are keener to commit and spend a bit more trail centres should be able to rent you a trail bike.