I have dogs, and I've self groomed for 6 years. My clippers I can change the blades on, I drop them off when dull and really only need 2 sets. Ask at places like decent pet stores where they'd recommend and see what they say. Also if you have sharpening services in the area for things like scissors and knives, many of those people do them. If you think you'll be going through lots of blades for $40ish bucks they sell a 'tool' to sharpen blades perfectly yourself.
Even doing 3 dogs every 5 or so weeks, I only mine sharpened every few years.
