Your higher end reels will have tighter tolerances and the machining will be flawless. They'll be smoother, usually lighter and better balanced. Twice as much doesn't necessarily mean twice as good though. In fact, usually the quality increase is disproportional to the price increase because it cost more to make things just a little bit better. It costs more to take the time to get things to fit perfectly and certain shapes are much more time consuming to machine. The difference between a $700 reel and a $70 will be obvious if you were to compare the two. Plus, you'll be hard pressed to find a reel for $70 that will last very long. Where does it end though? Some folks think $700 is too much for a reel, some think $300 and some $200. There's probably even folks that wonder why someone would spend $70 on a reel.

Hell, I've seen kids fishing with line wrapped around a tin can. They swing the line and everything around like a lasso and let'er rip. Then they bring it back by winding it around the can. Some folks probably think the tin can thing is crazy because they just use a stick with a short piece of line tied on the end. I would guess that someone that bought a $700 reel probably did so because they liked it???