How much does medical marijuana cost in Washington?

So I recently started having back pains and found out that I have scoliosis so I've been thinking of getting a medical marijuana card in Washington. I have been researching a lot about it but I can't find anything about how much it costs to get the marijuana (seeds or clones?) to start growing and also can't find where to get it. Anyone have a card that knows? It would be a great help. :)

: http://alcoholdrugstreatment.info/how-much-does-medical-marijuana-cost-in-washington