Is there a drug that's less expensive and can be used as a alternative to humira (adalimumab) for rheumatoid arthritis?

YES. There are multiple drugs for arthritis cheaper than humira. Pills like methotrexate, sulfasalaxine, Plaquenil (hydroxychloroquine) and Leflunomide can be used alone or in combination. There is also an injectable form of Methotrexate that can sometimes be more effective. Prednisone can also be taken. Non-steroidal anti-inflammatories can be used. Depending on your insurance, another biologic may be cheaper than humira.