Dont own a business, BUT I am a print product specialist at distribution level and also spent 4 years as a supplies account manager / product specialist at computer 2000 (uks no1 it disit).
Will be a gamble man as it's a fierce Market out there, but if you get a set client base to work from you should be laughing as the magic of consumables is it's repeat business. Make sure end users are happy enough not go elsewhere and you'll get away with a lot pricewise.
Make sure you are getting bids from vendors / distribution where you can - ie there are always supported prices from vendors for stuff like government, schools or large opportunities.
Currently waiting for an order to drop which will mean we supply all the game shops with new printers.
And don't limit yourself to just consumables. Push the hardware as well, people always want the latest stuff. Printers nowadays have wireless, Epson workforce pro range are AirPrint ready and cheaper to run than a laser with the same performance and quality.
BUT it is a fierce Market.
If you need any help give me a shout!