Can multiple myloma be cured 100%? What will be the cost of stem transplant which I heard is the best option to fight this cancer?

Cure in vocabulary. Traditionally we have thought of multiple myeloma as incurable. However the "c word" cure is now in the vocabulary. At ash 2009 dr. Barlogie talked about cure. An mdacc study from 1987-1997 (=old data) showed a 10yr os "cure fraction" of 2% (ash 2009 #3864). The majority of mm pts are not cured, but it is now possible in a small fraction of pts and may increase in the future.
Not curable. With an autologous stem cell transplant (self donor) these patients can have prolonged survivals typcally upto 6-7 years and even upto 10+ years. However, some patients with mini stem cell transplants using matched family donors can result in long-term survival too. Most patients though are never thought to be cured and may ultimately relapse. Costs can range from 125-150 k but may be more too.