Has anyone had to go off of their Coumadin (or other blood thinner) and substitute it with Lovanox or something similar?

My mother's supplemental insurance (she is on Medicare) does not pay for the Lovanox, which she takes in place of the Coumadin. The price tag is - hold your horses - over $600/week.

We do not see any other options... no other drug, other dosage, etc. The doctor is emphatic about this medicine.

Does anyone have any experience with this?

Daughter (30 yrs.) to awesome Mom (67 yrs.)
Diagnosed 7/2008 with T3or4N3cM0, squamous cell carcinoma.
Completed induction chemo (TPF) 8/08 and radiation/chemo 11/08. Successfully removed tumor via neck dissection 9/09 and went home from hospital in good spirits.
Joined the Lord Oct. 2009.