Best Resource for LSAT Problem Sets? Forum

[DrShrimpPuertoRico]

I've recently begun studying for the LSAT using PowerScore's LSAT bible series.

I started by practicing the LR section and discovered I had difficulty mastering the 'Must Be True' and in particular the 'Most Strongly Supported/Inference' section. The problem set for questions of this type was relatively short, and I did not do well enough to feel comfortable with them. Therefore, before going on to study other LR questions, I'd like to improve on these types of questions. So, I've been trying to find out which resource out there will give me access to the most problem sets (not full length tests).
I have a booklet of full LSAT tests, but I'd rather use them to practice emulating the actual exam rather than picking them apart for individual questions.

Also, I know 7Sage offers many problem sets, but the cheapest package ($179) only offers the easiest set of problems, which I don't thin would offer much help.