Treatment of Peripheral Neuropathy d/t Gammopathy - followup

PROBLEM: At my Neurology appointment on 4/13/10 I was informed by Dr. Edgar that Medicare would pay for my IVIG treatment for my peripheral neuropathy for only a limited period of time, usually for either 6 or 12 months. I began treatment in 9/09 and it now being 4/10 I have received IVIG for 8 months. So, it appears that Medicare will stop payment after my treatment in 8/10. I will check with Dr. Edgar’s office to confirm this date.
I have been worrying about this in view of the cost: 60 grams per infusion costs $9400 and receiving it every 3 weeks or 17 times per year equals about $160,000/year. So, my problem is what do I do when my IVIG Medicare coverage expires in 8/10?

HISTORY, brief: My peripheral neuropathy (pn) began in 1984, some 26 years ago, with numbness and tingling (n&t) in the soles of both feet. It then appeared unchanged until 1999 when I noted onset of numbness and tingling in the fingers of both hands. That then appeared unchanged until 2007 when n&t increased in both hands and my balance and gait became notably poorer.
At that time a nerve conduction study (ncs) revealed both myelin sheath degradation and axonal deterioration in the peripheral nerves of all 4 extremities. Prior studies had been normal.
Blood studies at this time revealed a Gammopathy: elevated IgG & IgM, both being in the thousands while AMAG was > 70,000. My pn was attributed to the Gammopathy.
In 2/09 I received a course of Retuximab to no affect. Then in 9/09 I received IVIG which showed significant improvement in 3 weeks, the n&t being reduced by about 50%. Infusions every 4 weeks showed a breakthrough in symptoms after 3 weeks so we increased the frequency to every 3 weeks which has worked since 2/10, the n&t remaining stable at its improved level.
I presume that my neuropathy will progress if the Retuximad is stopped. Presently it appears that this is the only treatment that will hold my neuropathy in remission.

OPTIONS:
1) Accept stopping the IVIG in 8/10 and watch the course of the disease – least acceptable option.
2) See if I can pay for the treatments – very expensive option - $160,000/year,
3) See if Medicare would continue to pay part and I pay the remainder.
4) Try Retuximad again to make sure it does not work; check initial dose, etc. to make sure I received a proper course of treatment. Retuximad, in those where it works, is effective for 12 – 18 months. Then another course can be given.
5) Seek outside source of medication where cheaper, such as China where it may cost 1/3 as much.
6) Does Canadian Medicare give lifelong treatment – and move there?
7) Dr. Edgar mentioned replacement with an immuno-suppressant, such as Imuran. However, this depresses the whole immune system making you more susceptible to infections. I, also, heard that Imuran increases your risk for cancer (?).
8) Is there some other treatment in research or on trail that could be tried?
9) Other?