A professional consumer. Is a consumer (i.e. buys a lot of gear and equipment) but only buys professional standard equipment.
Not necessarily a professional themselves, for they may be punters rocking expensive, high quality gear.
Prosumer: I just bought a Canon MkIII 5D to take photos for facebook.
Mate: You're a dickhead. You really didnt need a camera that good just for facebook. ffs.
Prosumer: I'm looking for a new bike, any ideas?
Mate: Maybe go and get a Giant with 105 componentry; it should do the trick!
Prosumer: Mate, cmon. If i'm going to get a bike i'll prosume and get something with super record.