One thing that I didn't see mentioned, is that most of the cues I've seen in the 20-30 dollar range have screw on tips. Screw on tips = junk. Don't do it. You'll just end up throwing it away in a couple of months. if you really want to get a cue there are a few decent ones in the $60 - $80 by people and companies that make pool cues, not companies that make sports equipment and decided to come out with a pool cue.
four things to look at when buying a cue:
1. The Tip, is it a screw on? if yes go to the next cue in line.
2. The Ferule, this is the piece the tip attaches to, is it cheap plastic? I saw a play kit you could get when with sticks balls racks etc, it came with spare ferules, Junk! cheap plastic ferule, go to next stick. in over 20 years of playing and breaking with my own sticks, I've only broken ONE ferule, and it was Ivory.
3. The Shaft. Look at the grain of the wood in the shaft, is there a line that runs all the way up from the bottom to the middle of the top? Cheap cues will sometimes have a grain that cuts all the way across a stick. If the stick fails catastrophicly, this will be where, then you have firewood.
4. The joint, this is where the stick attaches together. is it a good tight connection? does the stick feel like a single piece once it's put together. or does it seem a little wobbly at the joint?
One more thing on the difference between wood and fiberglass. Wood is more forgiving of misuse and abuse. I watched as someone didn't set their cue well against a table and it fell down as they were racking, the fiberglass cracked down the lenght of the shaft when the cue hit the floor. That and I've tried a couple of fiberglass cues that people I know had, I just didn't like the way the felt in my hands. They didn't seem balanced particularly well, and seemed to drag on my hand more than my wood sticks. I own 7 sticks, ranging in price paid from $70 - over $800. They all play as good or better than the day I bought them. How could they play better? New tips, I'm using Moori Medium on all the sticks I have except my breaker and jump cue. I still have hard tips on those.