I am looking for monthly flea meds for my outdoor feral cat Steve

Hi! I'm interested in getting "Comfortis or Credelio (Spunorad / Lotilaner): These are prescription oral chewables that last for a full month. You will need to speak to a vet to get these, but many vets will prescribe them for community cats if you explain the situation."That's what Gemini said will work on a skittish outdoor cat. Does anyone know a discounted place I could get this?He needs it desperately. I want him to be clean so bad, so then maybe I could make him an indoor cat, which will take time, but I need the fleas gone first.I really love this cat, so any help or donation is appreciated.If you have any extra, please do share. I'd (and Steve) would be eternally grateful.

If anyone can donate (I don't know how much I need). I'm hoping $100 or less. I need the chewable kind you mix in food.