The last I paid for R22 was $360. I filled my unit along with a can of dye to find 9 leaks in the A coil and condenser. It ran for about 15 hours before freezing up again. My son-in-law used some to fill his father's system and it's been sitting here since.
I have a few 14 oz. cans of R12 that I bought before it was out of stock.