There is a difference between cheap scopes and high end scopes. The image you see on the high end scope will be clearer and sharper, especially in low light. The better scope will likely be more waterproof and last much longer.
That said nobody really NEEDS a $2000 scope. There are many scopes in the $200-$400 range that I'd be perfectly happy with. Once you drop below the $200 mark there aren't many I'd recommend.
Generally speaking as price goes up so does quality, but in smaller and smaller increments. There is a huge difference between a $100 scope and a $200 scope. The difference between a $300 scope and a $500 scope is barely noticeable to most people and you would have to really look hard to see the difference between anything over $500 in my experience.
I have one high end scope, a Zeiss Divari that sold for a little over $1,000 new. I bought it used for less than half that. It is a great scope, but is only slightly better than a $400 Leupold VX-3. I wouldn't have spent the money for a new one, and like Art I could be quite content with anything in Leupold's VX-2 lineup.