Toner is the main area where you can reduce costs. Unless you can afford a Kyocera, then toner will be about 2p a page. I got it down to about 0.5p on the EPL5500 printer, by refilling cartridges several times.
I now use the EPL5900 but this newer model is 16ppm instead of only 12ppm click here
I use refill toners from here click here about £10 each instead of £70 for a new cartridge. You should get at least one refill from each new cartridge. I cannot say whether the new model is still refillable. Manx might know. The EPL6100 looks like the same design. I'm still using refills for the EPL5500 that I had before my current printer.