Cheapest ketotifen options

For those of us who take ketotifen, I was wondering how much you pay and where you get it from. After sort of local shopping around for prices I pay about $73 per month to get it compounded for me. I take it 4x per day

I have to get a lot of meds compounded and the costs are adding up because I can’t take lactose. I’m just wondering if any of you have found cheaper ways to get lactose free ketotifen.

Part of me wants to see if there’s a way to convince like mark Cuban’s pharmacy to get someone to mass produce ketotifen without fillers.