You can pay from about 25 bucks up to 500 bucks for a paddle.
You should find a paddle of appropriate length.
If you are average height you will need a paddle of about 230 CM or about 90 inches. I am 5'10" and I prefer a 240 CM paddle but that would be just a little long for most folks.
Bending Branches offers the following sizing recommendations.
http://www.bendingbranches.com/kayak-sizing.htmlIf you can afford it you should get a paddle that weighs 30 ounces or less. Generally the lighter the better and the more expensive it will be.
You need to consider whether or not you need a 2 piece paddle. One piece paddles are lighter but much more difficult to transport. One advantage to a 2 piece paddle is that they usually offer a variable feather angle. I don't use feather, so I have a 1 piece.
The best paddles are all carbon fiber but just because it is carbon fiber doesn't make it any good.
If you want the best paddle money can buy it will be a custom made ONNO, but they are not cheap. I have a 230 CM ONNO that weighs 23 ounces. The ONNO is light stiff and strong. Just talking to Patric will improve you knowledge on paddles.
http://www.onnopaddles.com/Werner makes various grades of paddles, some of the higher priced paddles are pretty decent.
Bending branches makes some of the "best bang for buck" paddles.
http://www.bendingbranches.com/performance-touring-kayak-paddles.phpThe touring Hybrids either Slice or Glide are very good paddles at a reasonable price. Weight is down around 30 oz and they are available in proper lengths.
I haven't seen a Carlisle paddle that I would care to own.
All of the better paddles have curvature. That is they curve towards the tip perpendicular to water.
As a beginner you will want a paddle with dihedral. Paddle dihedral is when the blade bends back on a line perpendicular to the shaft. Dihedral makes a paddle easier to control. Flat blades are more difficult to control and winged blades more still.
Here is an excellent article on paddle blade shape
http://www.touringkayaks.com/paddle_shape.htmAnother option that you may want to consider is the bent shaft. Some people find them more comfortable.
For your first paddle I would suggest that you not pay less than 100 bucks, or you will be replacing the paddle in short order. Then you will probably want something different as you skills progress.
None of the sports stores carry a paddle that I would own with the exception of REI and they are more expensive than other sources. You will probably need to go to a kayak dealer to get a decent paddle.
Would be good to try before you buy. Just a few ounces difference in paddle weight can make a big difference in how long you will be able to stay on the water.