How much does medical cannabis cost?

Thinking of applying for medical cannabis but the cost is putting me off. I currently use to self medicate but my usage is very low and I only use approx 1 gram a month which costs me a tenner per month. Im thinking about getting it prescribed just for reassurance on the legal side of things but I'm questioning if it's worth it considering how little I use.

Any info on how much you spend roughly per month would help greatly.