I was also getting the HS mixed by the pharmicists to either 5% or 7%. This cost was high, I think around $150 to $200 dollars per month. It's been a while so I forgot.
Then, one day the pharmacists and I started sharing ideas to make this process/prescription easier and cheaper. He stated people are having a hard time affording the mixed solution as the cost rises just for the process of mixing and keeping sterile.
For me, we came up with this: I buy the 10% solution; this is cheaper because it's already made sterile in that solution content and no mixing is needed by the pharmacist. Then I dilute it with either broncho saline and/or albuterol.
(2 ml of 10% HS)+(1 ml of either broncho saline or albuterol) or for larger treatment I use (4 ml of 10% HS + 1 ml of broncho saline + 1 ml of albuterol). These = 7% solution. The premade 10% vials have 15ML of HS in each one. My pharmicist said to use what you need out of one 15ML vial for a day (24 hours) then throw the rest and open a new one for the next day. There is some waste, but the cost is much cheaper. (just salt water.) I get 30 vials (month supply) for $24.77, broncho saline is $7.04.
He did tell me adding other things besides the broncho saline to the HS will dilute the solution as well.
He said if this concept works for me, maybe others could do this as well and be more affordable. You may have to check around at different pharmacy's to see if they carry this.
Hope this helps.
S