Hi d.vanlee,
Thanks for your post! It sounds like you've improved your score quite a bit, but still struggle to complete the LG section in time. As you probably know, you can't work on your speed in isolation: pacing is almost always a function of accuracy and superior conceptual understanding of the material. The LG and LR bibles are a wonderful resource to lay the foundation of your LSAT test prep, but oftentimes students find that they need supplemental material to help them apply the techniques they learned in a more efficient manner.
Check out the LG Workbook, which includes 30 fully-explained logic games, along with numerous practice drills whose goal is to facilitate rule and set-up recognition (
http://shop.powerscore.com/?action=prod ... 00O2WQCIA3). Also, you need more games to practice with. You didn't mention how many tests you took, but you certainly need more LG-specific practice. The Logic Games Question Type Training I and II provide question collections you might find useful, along with the Setup Encyclopedias (v. 1 - 3). All of these publications can be found here:
http://www.powerscore.com/lsat/publications/.
Based on your score range, I'm willing to bet you are struggling with some of the highest- difficulty logic games. Perhaps the best resource for students like yourself is the Advanced Logic Games course (ALG). Check it out here:
http://www.powerscore.com/lsat/advanced-logic-games/. The ALG provides over 20 hours of in-depth analysis on how to approach exactly the kinds of games you have trouble with, and is bound to be a great reference point as you tackle this section in the future.
All of these resources will be cheaper than a tutor, and could be just as effective provided you are comfortable with the virtual format of the ALG. That said, if you require individualized attention, tutoring is hard to beat in that regard.
You never mentioned how you did on your LR and RC sections. Nobody drops to the 80th percentile from mistakes in LG alone, so it's possible you need to work on other question types as well. Let us know if there is anything we can do to help!
Good luck!