Nearly all State Bar Associations provide access to a low-cost legal research system as a member benefit. The most common systems available through the state bars are Casemaker and FastCase. Check with your state bar or look at this useful map to determine what you have access to.
For more on Free/Low-Cost Legal Resources, see Free and Low-Cost Research Resources for Any Budget.
See the "Bar Membership Benefits" box to the left to see how some of these low-cost options can be accessed for free.
The BYU Law Library pays for subscriptions to some low-cost legal research systems for BYU Law Students.