I think there is a difference. However, whether that difference justifies the price depends on a few things:
1. What techniques and species are you targetting with this rod. Generally the higher prices are due to higher end components. These components usually result in lighter, more sensitive rods. The sensitivity is generally what you pay for. Now, if you are fishing a technique such as crankbaiting, then sensitivity is not generally the most important factor. If you are fishing bottom contact bait techniques, then sensitivity is paramount.
2. How good is your sense of touch? Seriously. Will YOU notice the difference in the sensitivity. I would hazard that the general angling population could not sense a significant difference between a $150 and a $300 rod.
This translates into the cost:benefit ratio. Everyone has one that they generally adhere to unless stricken by love at first sight - which turns us from intelligent shoppers into impulse buyers. How important is it to you to get that last little bit of sensitivity? If you are a tournament angler who needs or wants every possible advantage, then that extra bit of sensitivity may be worth an extra $150. To most, it may not be. Now, if you are a gear fanatic, then that is a different story and the cost:benefit ratio skews somewhat.
In the $100-150 range, you can look at Shimano Compre Rods. Check out the Rapala Shift rods (at LeBaron). These rods are amazing! I am super impressed with the. There are also Powell rods (which you would have to check online at sites like Tackle Warehouse). But, in that price range, I would look at the Rapala.
Good luck