For some reason, near me, there's a little street shop that sells copies of every LSAT test and their answer keys. It even has the one from October 2010. Is it illegal to share or post these online? I'm assuming it is, but I figure they'd be helpful to a lot of people when studying for the tests..
Do they reuse the same questions a lot?
LSAC does not reuse questions from previously administered LSAT tests that have been disclosed. Similar concepts and constructions are repeated though since it is a standardized test.
Since the little shop is already selling copies of the October test, they are probably breaking the law by pirating the tests, printing copies of them and not paying LSAC the required licensing fees to reproduce them, but you would have to ask them about what they are up to. People that have ordered a licensed copy of the October test from LSAC (cost = $8 plus shipping) have not yet received a copy since it takes time to print them with the nice book cover and fulfill orders.
If the shop is selling individual copies of recent tests for less than $8 each and/or is selling them in electronic form they are certainly violating copyright law by not paying licensing fees to LSAC to do so.
Individually sold recent tests should have a nice thick color cover that looks like: